@paulcreed
I had a BAT BAT VK5i a long time ago, with a similar experience - based on reputation I thought I was in for an amazing preamp listening experience, but it definitely was NOT a joy to listen to. Tried tube rolling, including Tung-Sol 5881, etc. At best, maintaining all those tubes and keeping noise low was a nightmare. That said, my system was a mess back then with a lot of problems - but I certainly wouldn’t ever give the VK5i another try.
But all else being equal (and it never is), I do believe weight (meaningful weight) and parts quality are at least somewhat correlated to sound quality. I definitely don’t see anything wrong with Kevin’s PrimaLuna pitch on that front.