Every once in a while someone asks how I like the e34s after driving the MR.... now I'll simply give them this URL..
My glib answer to the question of how the e34 compares to the MK-II MR2 Turbo would be: they don't compare. They are two very, very different cars. The MR2 Turbo is much quicker than my 535iA (and goes without saying faster than the 525iT). As in way faster. More like an M5 in straight line acceleration. (200 HP, 200 lb/ft torque, ~2800lbs). There is some turbo lag, but it's really more like enough power at low RPMs then too much coming on too fast at 3K+ (in lower gears). Braking is superb - stopping distances are among the best of any production car on the road even today. Brake feel is similar, though the BMW is more stable under high-speed braking conditions. In fact, the BMW feels much more stable at high-speed in general - the MR2 has a short wheel base and a light front-end. It's a bit skittish in the triple digit range, whereas the bimmer is just cruising at 110... and no, I don't regularly drive that fast. But I have driven both cars that fast once. Maybe twice...
In the twisties there is no comparison. The MR is much more tossable and has a lot more power to accelerate between corners. The mid-engine layout also makes for a different handling experience - for example, you do NOT want to lift off the accelerator in a corner, as this unloads the rear suspension and will quickly cause a spin (since the engine is heavy and behind you). You just want to set the car and keep power on through the curve (note - I'm not a great driver, and I'm sure lots of readers driving an 535iA could whip me in an MR2 Turbo on the track - Steve and Margaret, I mean you two ;-). Grip is excellent, handing is well communicated. Steering is good, but it takes some getting used to the short nose and the lightness of the front end.
Comfort - MR is rather loud in the cabin, what with the engine about 18" away from your head. Seats don't allow for a whole lot of adjustments, and tall people tend not to fit well in the car. One sits pretty low which takes some getting used to.
Feel - it doesn't have the solid BMW "I am so overbuilt I will never start rattling" feel. It has the solid Toyota "I am well put together but my doors do not make that satisfying 'chunk' sound when you close them" feel. Interior is nice, functional and simple. Stock audio sucks (I'm an audiophile), significantly worse than the Bimmer. Tranny is a little notchy, shifter position takes some getting used to. Brake rotors are notorious for warping, otherwise you can get 50k miles from a set of pads. Tires in the rear wear fast. ;-)
With the t-tops out, it's lots of fun (I'm not particularly a fan of open-top motoring, but it's fun in the MR). The whistling turbo, growling/howling motor, and whoosh of the waste gate opening between shifts makes for some exhilarating driving.
In summary I'd say the MR has lots of driving character, way more performance than I'm capable of exploiting, it is well built, very reliable, fairly economical to run, and produces lots of grins on the road.
The 535iA is stealthy-fast, very stable and solid, comfortable and quiet, bulky in tight corners yet surprisingly agile for it's size and weight, awesome at high speeds (including high speed sweepers), excellent when braking, and makes a lovely road-trip machine.