I demo'd both the Glider and the Avant. I'm on a stock saddle now that came with by Blue RD-1. I wanted to try the science on SMP's extreme cut out. I had my sit bones measured at a Specialized shop and it was around 155 or 150. I think my stock saddle is a 130 or 143 and I've never had a problem with my sitbones - numbness, yes, sitbones no.
I chose the Avant first because I thought the size would match up better. I was on the trainer for about 5 minutes before my sitbones were in pain. It felt like the cutout was way too big and therefore, spreading my sitbones further apart.
So, I decided to try a few sizes down and got the Glider. It was definitely an improvement fit wise, but something just didn't feel right. I felt like my sitbones were having to straddle a very small piece of the saddle because the cutout is long AND wide. And I felt like I needed something a bit more narrow.
Maybe it was the way I had it on my bike (and I never could get the saddle tight enough), maybe it's just the way my lower half is - I really wanted to like the SMP, but I couldn't get down with it. After the Glider failed, I gave up. Maybe they just aren't for me.
Good luck with your search! If you're looking to demo more SMP's, you can always check out www.theprossstuff.com. You pay for shipping and give a $20 refundable deposit. Keep the saddle for a week. Just FYI![]()