I drive an early model Waja. I've also driven an auto gen2, though it's still in the low mileage range and probably isn't completely run in yet.
1) Oklah, power/torque comes in low in the rev band but you lose it very quickly towards the top. Decentla, but noisy engine screaming for its life all the time when you push it :p Gen2's power delivery comes in much later, something I hope will be rectified once there's a real CAMPRO engine that does the profile switch, and keeps going. Low end pick up is quite a let down, almost annoying to me really. Maybe a proper exhaust system and a drop in filter might help a little.
2) Kinda bad, compared to say my brothers DC integra (non-vtec la). Definitely Gen2 better.
3) Well I dunno, my waja has been lowered all it's life hehe. Great stability, great handling. Riding on 17's as well. Can be a little rough but thats how i like it. The Gen2 stock however has equal handling to my lowered Waja though, and I can imagine if done right in lowered form would be even better :). Haven't done much higher speed stuff in a gen2 though so can't comment on that. Waja feels good all the way to 170km/h-ish that mine tops out at.
4) Noise is fine with me, Wira's, kembara's, kenari's are far noisier. Even lowered + low profile tyres dont sound too loud. This however is personal preference i guess but even when i was running on standard rims it was quite quiet :). Gen2's pretty quiet as well.
5) The driver seats suck on the Waja, and I mean it. The try to support your back so much that it doesnt feel like its supporting your back at the same time hehe. You cannot adjust steering wheel for reach, which is a problem for me because in a proper driving position for my arms, my legs are too close for full comfort :P. Middle aircon vents will always point towards the driver no matter what, so you can kinda freeze during night driving at times. This also means the passenger doesn't get much aircon. I personally have a real dislike for the Gen2's interior. The steering wheel manages to feel even cheaper than the stock Waja steering wheel. The overall design only LOOKS decent, but in use doesn't really work. A good example is the clock, you almost can't tell the time at a quick glance. The aircon controls are too far and require a good sit up and reach to get to. The handbrake lever is the dumbest thing I have ever used in my life. Form over function :-\. Seats are nice though, but Waja is much more comfortable for the rear passengers, especially if you have alot of taller friends :).
A proton is a proton, is a proton, however. So take it as you may :)