Anybody use Eko PowerGrips or similar things? Likes? Dislikes?

Anybody use Eko PowerGrips or similar things? Likes? Dislikes?

I've never used them on a fixed gear, although fixed-gear uber-randonneur Kent Peterson does.

I have had them on every MTB I've ever owned, and they are the ideal solution for me.

Likes:
Great retention, equal to clipless or tight straps.
They seem to get tighter just when I need them to. When I'm really honking, the natural motion of my foot on the pedal and the rocking of the bike snug them up just that extra bit. It's not something I even think about, it just happens naturally.
Easiest exit of anything I've used.
When starting on a hill, you can either ride the backs of the pedals, like with clips-n'-straps, or flip the pedal over and stand right on the PowerGrip. Being strong flexible nylon stuff, they don't seem to care much, and pop right back up when you lift your foot off to strap in properly.
They don't require cycling shoes.

Dislikes:
Good toeclip compatible MTB pedals are tough to find. I'm using NOS Deore XT IIs, and they're pretty good. If I find a good deal on some Suntour XC Pros, with WTB toe flips, I'll be in heaven. This would be a non-issue for a road fixie, as good toe clip pedals are easy to find, new or used.
If you ride the same bike in very different shoes, you may need to reset the tension. It isn't hard, just takes a 5mm allen, but it is an extra step. Shoe height seems to be the critical dimension here.
I can envision a certain, very limited set of circumstances that would cause them to tighten in a crash. Think twisting bike here. It's never happened to me, or to anyone I know, but there have been a couple of reports on the i-BoB list.

I really, really like them. They wouldn't be my choice for a go-fast road bike, but for many applications, they rock. And hey, if you hate 'em, you're only out 20 bones.

--Shannon