Jet Vehicon is a major retool of TFPRiD Car Vehicon. The robot components are basically the same, but all the vehicle parts are different. I think the retooling and alt mode is different enough to justify getting Jet Vehicon even if you already have Car Vehicon.
As for FE and Car Vehicon... both have their pros and cons. Visually FE Vehicon is the most impressive - bulkier and better paint apps/decos. FE has superior head and waist articulation, and the arms are better designed. But I don't quite like the feet on FE - they're prone to flipping in really easily, and the vehicle kibble on the back is somewhat more cumbersome. But Car Vehicon is generally more solid in robot mode and there is a certain degree of elegance in the simplicity of its design.The main thing that bugs me about Car Vehicon is the lack of waist articulation, and I wish the head had a freer range of movement too (naturally Jet Vehicon shares these limitations too).
Here are some photos...
FE (L) & AM Car Vehicon (R)
AM Car (L) & Jet Vehicon (R)
L-R: Car, FE & Jet Vehicons
L-R: Jet & Car Vehicons
And here's a pic of FE Vehicon in robot mode
Dynamic pose of AM Car Vehicon
Action shot of FE Vehicon (if you recall, I used the same 1 toy over and over again then composited them together on MSPaint)
Same here.I'd much rather buy new kinds of Vehicons over new kinds of Bumblebee!
Mate... I can't stand the stickers! I also really don't like the Arms Microns either (and they require tiny stickers! Extra frustration!) (>o<)