Stitch City was promo'ing the Brother GT541 at the ASD/AMD show in Vegas today. I asked them about the cap platen and they went ahead, hooked it up, and printed a cap. They did a print with the half the design going onto the cap, the other half onto the bill, it looks great, they put it in the cap press twice, once for the cap portion, then they pressed the bill itself to dry the ink there (I was curious if that's what they did). We might be sold on it, even though it wasn't really on our list for this event
Edit: They gave us the cap they printed, so I took a photo of it at our hotel room and attached it to this post. They used an Otto cap that says "One size fits most", unfortunately I got a fat head or something, and it doesn't fit me