Sure, here are some thoughts:

Alt mode:
-DX9's alt mode is G1 and overall pretty nice. I like the alt mode quite a bit, as it's like having a mini MP-11 on the shelf without any real compromises.
-IF's alt mode is smaller overall, blockier, and more bulky in appearance. I'm not as familiar with the source material but I kind of like the way it looks.
-Neither one has a perfect ideal alt mode. DX9's has the odd placement of the arms that breaks the sculpt of the front of the jet. IF's has a lot of under-jet kibble.

Bot mode:
-IF's has much more posability, including a waist swivel, full head articulation, better feet/ankle/arm articulation (including full "Van Damme" and "Monty" in BSF's parlance vs limited front-to-back on DX9), a more posable back wing arrangement, and the tail fins and stabilizers stay on the legs, which (imho) looks better, where as DX9's have bare/naked lower legs especially when viewed from the side.
-DX9's has a fairly flat back thanks to creative engineering that manages to compress all wings and fins into a very flat plane, although viewed from the side it looks a bit like the figure has a glider strapped to its back, and the head is situated further back on the torso, so it looks like a bit awkward.
-IF's head size seems more appropriate for the size of the figure, DX9's seems a bit on the tiny side and has a flatter headshape front to back.
-DX9 has more visible ball joints in the arms
-DX9's Skywarp purple color differs on the null rays vs the arms/legs purple.
-DX9: Tiny hands. IF: Oversized hands.

 

bot modes nice but jet modes are blocky on underside hasbro legends seekers are much cleaner to look at in jet mode if i dd buy these sets it be kept in bot modes jet modes unimpressive t ome

 

Also wanted to add to the cons of the IF side, I really dislike that the peg for the nullrays is on the bots bicep instead of on the gun. It looks bad if you ever take the nullrays off. Odd design choice.

 

They somehow managed to improve upon the Seekers which were already fantastic.

 

@edgecrusher - Nice write up and photos. Sums up the differences pretty nicely.

I don't have the DX9 set, I'm not in on getting a whole bunch of legends figures on top of everything I spend on my MP shelf, so I had to think long and hard about whether to get IF or DX9. I went with IF because I decided that I wanted stuff that was really striking and invited me to play with it. Since I'm not looking to replicate my G1 MP collection in a smaller scale, it doesn't bother me that the IF stuff is more IDW-inspired or highly stylized; that to me just makes it jump off the shelf a bit more. That's especially true since I pretty much only display in bot mode..

So I think it comes down to whether you really want to have G1 accurate figures at the legends scale. If that's what you want, it's gotta be DX9. If you don't care about stylization but want to display in alt mode a bunch, it's a harder call but still probably DX9; IF to me designs with bot-mode priority and the alt modes are often a bit unspectacular. I think the IF jets look fine but it's true that they don't look great from below. If you want really dynamic, eye-catching bots that you can mess with and pose, that to me is more IF territory. It's not across the board but their figures generally have a lot more articulation and the heavy stylization gives them real presence; I love G1 but I have to say that the G1 designs often end up looking a little flat in this scale, IMO.

All that said, I do like DX9's Dinobots. They are my alt-mode exception; the IF figures look nice but don't interest me since they don't turn into dinosaurs.

 

TFSource just reduced price on this set from $90 to $80.

 

Cute, but not a must buy. Iron factory does good work though.

 

A lot of collectors swear by MP scale, but I think this Legends scale looks almost better: with a smaller bot, you get more detail because of the lesser amount of space to cover. Paint apps, for example, need not break the toy budget when the toy is this small. An MP-scale toy, on the other hand? You're going to see compromises, and they end up making parts of the toy incredibly bland.

But that's not why I replied: I think you're spot on when you say IF focuses on bot mode more than anything else, and you already revealed why they do this: the majority of collectors don't seem to bother with alt mode (i.e. displays)!   So, of course, the IF toys are super poseable and look great in bot mode... while their alt mode can be a total mess (i.e. Muramasa or Pink Assassin).

That said, these jets look fine... but they're too small. The DX9 jets look amazing by comparison... they're just BIGGER. And I guess I expect a Raptor jet to look more imposing than IF's tiny representation.

 

Wow, enough to make me switch PO's, wonder if BBTS or TCP will match?

 

I'm with ya... but I'm also hesitant to suggest they start milking the seekers like FunPub did!   I'm not sure if it's healthy to want that many Seekers... but at least these aren't MP-scaled, and somewhat more affordable. They're also better than my current Classics/CHUG collection, so I could always sell those off...

This is exactly why I stopped buying MP stuff. Not so long ago, MP had the appeal of bringing the odd character to toy form... but now, with IF, DX9, UT, etc. making Legends scale toys? You just don't need to buy in that MP scale if you don't want to. And frankly, if it's such a b*tch to transform the toy, it just feels like an expensive shelf ornament to me.   Which is fine, if that's what you like to do (decorate shelves), but I'm certain you'd already have amassed enough toys to decorate your shelves, so it gets kind of worrisome to see so many collectors compulsively buy expensive toys they plan to only display... without the proper display space to display them!  

Spoiler: Secret Agenda

I'm hoping the MP craze dies down and we get more Legends and CHUG stuff.

 

Which set to buy you ask?! Get the dx9 set for starscream, thundercracker, and skywarp. And get the IF set with thrust, dirge, and ramjet. They even looked different in the cartoon where as the second trio of seekers, the coneheads, looked more like the toys. Pretty much like red alert and hoist differed from sideswipe and trailbreaker..

 

I just wanted to add the oversized hands on IF allow them to be compatible with the 5mm standard for weapons whereas the DX9 hands have very few items they can hold.

 

If anyone wants to sell the IF Sunstorm, I\'ll buy it!!!

 

Wouldn't say "very few" since it opens them up for any older legion class stuff as well as anything Lego/Mega Bloks compatible. There are thousands of weapons of that scale.

 

I honestly never owned a single one of any of that so I was completely unaware of that. Thanks for correcting me.

 

waaaw....

when?

 

One of IF first products (blaster) came with a shield and 4 guns not specifically for the set. In the pictures shown on retailers those weapons, and blaster himself (aswell as his 2 cassettes) were fitted on WFC Ultra Magnus .. or Prime. Anyways regardless of intentions, most IF packs since have come with those shields and guns included extra, and all IF figures have hand for 5mm guns. dX9 instead uses smaller pegs holes for weapons/hands also shared by UniqueToys legends scale. this has been a constant since both brands entered the legends scale market.

 

The IF girls use 3mm hands.