I built a Transcendence Grounded Grid kit a while back and it went together without any problems or issues (was really well documented). It was my first foray into building any electronics from a kit (previously had only done speaker kits). I wouldn't characterize the sound as typical (old fashioned) tube though. It was very clean, quiet, fast, and detailed and had very tight and powerful bass with no bloat or boom. It was not rolled off in the highs and did a very fine job with sound staging (very 3D). It was relatively immune to tube rolling, although you could get the midrange fleshed out a bit more by using NOS tubes.
Neil
