I wasn't sure if I should do a seven-year thread necro in its own review thread, but I've 'renewed' my appreciation for RotF Jetfire after playing with it while dusting it and checking its batteries.

Considering what it has to do, it's actually pretty good. Besides obviously transforming between Blackbird and robot modes (and the design may not have been finalised when the toy was designed, although major details look pretty close to the final CGI model), it also had to have the electronics block and it needed to combine with Optimus Prime.

It seems to me like that last requirement is responsible for the screen-inaccurate plane parts on the robot mode, since in robot mode the top of the head is formed from the cockpit canopy and the engines form the thighs, but the engine nacelles and the splitting cockpit are needed for combined mode. I wonder if Jetfire's silhouette could have been slimmer and possibly more screen-accurate had the need to combine not been there. Who knows, there might have even been a little less bulk under the fuselage in vehicle mode.

Design compromised for gimmicks? Probably, but the designers came up with something that looks and works pretty well, given those limitations.