I've never compared them to any high-end speakers due to the lack of high-end speaker sellers in this area. We got Best Buy and Circuit City. And the Nat Ps blow everything they sell away as far as clarity and quality. BB and CC have speakers with more bass due to larger woofers, or a built-in subwoofer, but as far as sound quality, only the Nat Ps really produce good quality. I still have my Polk center channel connected, and the Nat Ps sound better than that. However, I think the Polk has more bass. But the Polk does not have a crossover in it (because I broke it), so it's flying blind.
As far as construction's concerned.. it was a pain. The sawdust, the cutting, the router work, the gluing, sanding, it was all a pain. The crossovers were easy. Everything else was a pain. If I had to do it again, I'd deffinately do some things differently, such as purchase some actual crossover pin boards from Parts Express and build the crossovers on those instead of plywood. Get the good router bit the first time around. Etc.
I dunno. I'll be building the subs and surrounds this summer, so I'm willing to do it again.