There's loads that people consider good or bad or whatever, but given the rarity, you just have to take what you can get in my experience. The only issues I can think of are the rust spots on the wings which you'll get anyway at some point and the cambelt and tensioners.
All the problem areas with them generally seem to be wear and tear stuff.
My problem areas have been clutch, radiator, cambelt and suspension arms. All stuff that would need doing at some point anyway.
Oh yeah, and apparently a q2 is essential. In my opinion, it's a lovely 'to have' but should not limit you in your choice. I'm only going on my indie's advice and am sure I will suffer a broken diff as a result, but I'm not made of money!
Ex 95 164 TS Super, 95 164 QV, 97 164 V6 Super – all very much missed.