One thing that my shoes don't have is a toe dip on my right shoe (FYI, I'm right handed). I can see how having the toe dip would reduce the resistance there a little bit. Additionally, for the Shot shoe, the teflon thickness is only 1/16". I can't speak to this from experience, but they say you should be able to get more weight in shots with thicker teflon. So I'm guessing that my next set of shoes will be thicker, but I'm a little worried that, combined with a toe dip, it'll be even harder to dial back my weight when I need to. But there's probably always adjustments for new shoes.
Recently, Shot Rock Curling Supplies set up shop at the club and I was looking at the Balance Plus shoes, all of which have a dimple in the center of the teflon part of the shoe. It was explained to me that this forces you to have your foot flat and therefore better balanced. For me at least, with my tuck slide, I'm not sure that I'll get the full benefit as my slide has me on my toes.
I didn't try them on, so I guess I don't really know. It'd be nice if someone (me?) were able to try on a bunch of shoes and write up a comprehensive comparison. But until then, I can tell you that I like my Shot shoes and I would recommend to pretty much all curlers that they get some curling shoes.
