I'm impressed. It's been a LONG time since anyone has offered a truly different auto pistol design(even though the concept has been done before). The poll is already closed, but I would prefer the 4.2" barrel model. I'm sure it balances better in the hand, and the additional mass, sight radius, and barrel length only add to improved shootability and handling. It is plenty small for CCW or BUG. I would be in the market for this pistol if you choose to go through with full production. Just please ensure that it is very reliable.
I don't have anything that I would want to change on the prototypes that you have built. If you should decide to make a full sized or compact pistol with this design, definately consider double column magazines, a slide stop lever(slide stays open on last round fired), and additional calibers. Calibers you should consider(if you want good sales) are 9mm, .40S&W, and .45acp. All other calibers are niche calibers and will likely strain your profit margin. A slide stop lever is important in clearing malfunctions.