I have a first gen (see below), non-wastegated, which as described above as the two piece airbox. I've had it since 1987. Is it a PITA to take on and off? Yes. Do you get used to it? Yes. As to performance, compared to a wastegated Sidewinder, it's a bit more sluggish off the line but I think it makes a little more peak power. It's a better choice for two rig because it has lower backpressure/drive pressure so your EGTs are a little lower under load. By how much? I don't know exactly because I've never had the opportunity to compare directly. Educated guess from what I've seen... 100-200 deg. at same load.
If I was going to buy this and try to rehab it, step one would be to get the paperwork from Banks so you can see if all the parts are there. Otherwise, you'll be tied up on the install scrambling for lost little parts. The exhaust will be a big deal to fab up since Banks doesn't sell most of it any more. Not so much the stuff out the back, but the crossovers and downpipe, etc. It was all mandrill bent from Banks and there aren't many exhaust shops that can do that. Years ago, I got an estimate to have mone redone and it was several hundred dollars... for non-mandrill. I found a shop in Easter Ohio that can do mandrill but I passed out when I cot their estimate and don't remember it. I called Banks a few years ago and they said they would make up a new system special from blueprints but it was about $900. Not sure if they will do that any more.
So, bottom line, $200 may be a good deal or maybe not. I suggest buying only if you can get all the parts needed to make it work. Get the exhaust pieces if you can for a pattern at least. If you can get the system installed, you'll like it, but if it's too much aggro, put that $200 into a fund, start adding to it until you can buy a new kit (Banks, ATS or Hyper).