I think that if your making knives for sale, it very important to carry your own knives. I've been at this a long time, and still find myself disgusted when I'm at a knife show and I hear a knifemaker say... "This is the best (fill in the blank) knife there is!" When I know full well that the individual doesn't even participate in the activity that the knife would be used for. The importance comes because carrying and using one of your own is basically the "test bed", where you take a knife from proto-type, making improvements along the way, until you have a completed product.
Another thing that I have noticed over the years is that customers seem to have more confidence in your knives if they see you carrying and using them...and although I've never kept count, I have sold a large number of knives right off my belt, or out of my pocket.
I don't have a lot of what one would consider "standard models" but those that I do, got there after I carried them around for several months, using and improving them before I ever offered them for sale.
What do I carry? Daily I carry and EBK II on my belt, and one of my Progression I folders. Every year for hunting season I build myself a new knife, always trying something new and/or different for what I carried the season before.