Reliability varies depending on situation.

If you guys are talking street driving. Yeah of course.
If you're talking drag racing. No. I doubt any make engine lasts 20,000+ miles.
If you're talking road racing, yeah maybe. If you take it to a reputable racing shop to build and tune. That's not cheap by any means. Even then the reliability is a factor depending on your build. When building a 400-500 Civic you aren't thinking about anything other than drag racing. It's the only thing it's good for at that point.

Most 400-500 hp Civic's I've seen are street cars. They see the drag strip a few times a year. If their engine isn't blown, their axle is, if their axles are good, the transmission is acting up. If not the transmission something else. Unless they run their big boy slicks they're basically a burn out machine as well.

I've watched this thread and HatchVX's thread. Both of you know more about these engines then I do. HatchVX almost blew his motor. You did blow your motor. I'm guessing none of these were your first motors either.

All I'm really saying is, just make sure you have some return on your investment in these cars. I really shouldn't talk I've got 15 times the value of the car in my current turd, but my motor is stock.