I've owned both - 93 Probe and my current 89T Supra.
In stock form, the Probe had slightly better acceleration and FAR better handling, with the notable exception of some nasty torque steer. Very mild mods put the Supra ahead in the power department by a significant margin. I haven't worked on the suspension yet, that's next on the list.
The Supra takes to mods much better - the Probe is a serious PITA to mod. Basically, Mazda built the powertrain too close to it's max power all the way along - so you upgrade one part, the rest of the drivetrain will break. Unlike the Supra that was overbuilt to such a large degree that it's almost silly.
Newsflash - only the powertrain and interior were designed by Mazda. The exterior is all Ford, and comes with all the little fit and finish problems that you would expect from Ford.
The Probe is excellent in a crash, at least from the protection of the occupants point of view. I know this from personal experience... 60mph to zero in the length of time it takes to crumple the engine bay. I got out, took my mountain bike off the trailer hitch, threw my gear in my buddy's truck, signed the paperwork for them to tow my wreck to the junkyard, and went riding on the mountain. The other guy's brand new minivan was in pretty sad shape as well. I expect he'll think twice about stopping at the end of an onramp next time.
