Ronald,
I've got four knives I carry on my SB3 rig (please refer to the Lightfoot link on this forum, I talk about those knives).
About concealment, it depends on how you're built. If you're a slump-shouldered humpback, you're going to have a bit of a problem. Me, I'm not a sloucher, but I don't exactly stand up straight either, but I can carry my long knives under a loose overshirt (it gets bloody hot here in Austin, jackets are out of the question) and they don't print. My wife is in the process of making lightweight shirts with small panels of pellon right in the right places to even better conceal both knives carried SB3 and guns carried IWB. Not because the shirts I've been wearing haven't worked, but because I'd like to maximize the concealment.
As far as comfort is concerned, I can sit in my Lay-Z-Boy no problem with the rig on. In high-backed wooden chairs, it's a little more challenging. I've also had some movie theatre seats give me fits, while others are no problem. When you sit down, however, the knife will print if you slouch! Sit down without bending too much, and sit straight and you won't have a problem. It can give you a little backache if you're sitting ramrod straight in public for too long if you're not in very good shape.
Whew. The voice of experience is long-winded.
Matt
