... Matrix Prime says that the missile launchers on the dealer version he got off eBay are extremely powerful - something he believes will be toned down for the official release. Are the missile launchers really as strong as he says? I haven't got Stascream yet, but if the launchers will indeed be toned down later, I might have to pick up Screamer now for his improved killing power.  

 

I wouldn't say "extremely powerful"... They're pretty good, but not as good as the video would make you think.

From about 3-3.5 (1 meter-ish) feet up at about 10 degrees, they shoot about 6 feet (2 meters). My Allspark Big Daddy from the same location shot about 7 feet.

Mine is one of the ones from Heerotoysmaker, if that matters.

 

Nearly any Transformer with spring-launching missiles can be opened up and stronger springs inserted. Local hardware stores keep a variety of springs that are compatible.

When I was 11, I lost the spring in my Frenzy cassette that kept his head up in robot mode. I swapped a spring from a ball-point pen in there and found myself able to launch Frenzy's head far enough to hit the ceiling!   Luckily, my grandpa owned a hardware store and helped me find a better replacement spring.

 

That's a great story.

to the original poster:
I think your best bet is to wait for the retail release and then buy new springs if you are disappointed with his range. That'll be a lot cheaper in the long run.