It's.. fine. You can tell the gas sloshes around quite a bit in the tank as the gas gauge will swing by close to 1/2 (1/4 tank up to 1/4 tank down) tank if you get on either the brakes or gas hard. I typically don't run it below 1/4 tank as a result. I had to replace the
fuel pump I got as part of the Tanks setup this summer as mine burned up. That said, I think that was a result of fuel pump relay issues I was having that caused the pump to short out rather than the tank killing it. My first pump was quite a bit noisier than the second so I'm not sure if I just got a bad pump or not, but again, I think that was the pump and not the tank. The Tanks setup works just fine for driving around town and cruising on the highway (what I do). If you want a hardcore performance option I'd look elsewhere.
It's been a few years since I've kept up with available options but I remember Rick's released a non-stainless, every-man version of their setup a few years back that was in the $800-ish range. If I were to do it again with that option available I'd spend a few more bucks and go that route instead. I'm sure the scene has changed since I put my car together. As with everything, mine's not bad, but I could do it better with what I know now and what's become available since my build!