I like the one piece mold. Less seals means less things can go bad. The soft close seat is also a nice touch. We’ve had it in about a week and have not needed any double flushes. When installed, I’m not much for reading instructions, but swear I had appropriate clearance but toilet was hitting the wall. I know my walls aren’t plumb, so definitely something to keep in mind if installing in a situation where plumbing is being routed according to the specs. Still went in fairly easy, but had me nervous on that first flush. I’d recommend this product