A rough rule of thumb is that the length of the alt-mode is usually close or equal to the height of the robot mode with several obvious exceptions like Lockdown and Starscream. So for example, Bumblebee is 16ft tall while his Camaro is 190 inches long (15.83 ft) Optimus is 28ft tall while his Peterblit is 350 inches long (29.16 ft) Sentinel has a vehicle length of 466.5 inches (39 ft). I'd say that with that in mind he would be likely closer to 35ft than 30. Then again, Optimus never size shifted but his AOE truck mode is 505 inches long so... Either way all I want is for SS Sentinel to be at least the same size Evasion Mode or TLK Megatron, as at the bare minimum Sentinel should be that tall. I can accept if he doesn't turn out the same size as Megatron since he'd look pretty off with SS 32/44 anyway.