$100 a piece? Thats a pretty good deal on the tire, but do you have a decent place to get them installed? I found some nice deals on tire-rack, but no installers would touch them for less than $30 a tire, and then you get a crappy warranty (have to mail the tire back).

On tire brands, I went with the BFG TA/KDW. I got KDW2s for the rear and the original KDW on the front (don't know why, but I didn't complain). They're meant for when I take the E34 to the track, which I have yet to do (except for some 1/4 mile runs). I'll let you know how they perform under load.

Driving around town, they've been pretty good. Good traction, a little noisey. Can't comment on wear since I just bought them < 2k miles ago. No noticable problems in wet weather. AWESOME agressive tread pattern on the KDW2s.

I ended up purchasing mine at Costco for around $150 a tire (including promotion they had at the time). A cheaper alternative is the BFG gforce sport, which can be had installed for around $120 a tire.

While Costco may not have the best trained techs, if you can manage to find a non-retarded tire installer, their warranty is awesome. You get a nail in a high performance tire, and they replace the tire, no questions asked (at least this is what I've been told). Haven't used it in practice though.