I've heard the same thing about the belt drive setups. Our friend called it a "do it yourself kit". They get you 90% there. I'd still like to run one on my next engine though.
It's definitely not a bolt on and go deal so not recommended for the guy (or gal) that expects to just bolt parts on and go. It wasn't a huge deal though and easy enough to resolve. I'd say it's about right saying it gets you 90% there.
That being said, I'm pleased with the system over all. Seems to be good quality stuff and I'm happy with it. Performance parts sometimes need massaging. 12 years ago I installed a Danny bee FE system on an engine and had to make modifications to the tensioner pulley assembly, all part of it, just how it goes sometimes. Keeps things interesting.
Side note/ I have had zero troubles with the one on my 445 FE that I made from a 351c belt drive system.