Knowing what works and sticking with what works are two entirely different things.
Sometimes you just want to try something new. I am usually let down by new parts I try but that doesn't stop me from continuing to do so.
Most recently I strayed from my tried and true Shimano pedals and I realized I have now tried most of the SPD (mountain) type pedals out there. Hmmm, that would make for a decent rundown/comparison test here I thought...
So yeah, hopefully this is useful info for anyone curious about the differences in the plethora of pedals systems available. I will give a quick recap of the nature of each pedals system as it comes to mind. I don't feel like looking up specs online...anyone can do that for themselves, this is merely some of my experiences with them.
Lots of people ride Times, especially XC type people. This was the first set of clipless pedals I rode when I was 15 and I liked them fine. I had the low end ATAC Aliums and they were bomber. I was eventually lured away by the promise of light weight and better mud shedding from Eggbeaters. I recently tried another pair of the new Time ATAC Roc S pedals and was somewhat unhappy with them. The release tension was very high and there is no way to change the rotational angle of the cleats on the bottom of the shoe. This is dumb, not everyones feet point straight forward. Those of you with the shoe rubbed crankarms know whats up. Mechanically TIMEs are awesome, except for the ones made with the square bars on the pedal body. Don't get those, they break easy.
On paper, Eggbeaters look awesome. They look awesome in person too but I think they suck. I went through numerous pair and was not happy with any of them. If you bang a rock it releases your shoe. The ones I had need to be rebuilt frequently, which is easy to do but not really something I want to do to pass the time. Then there was the actual breakage issue. Different pedals, different problems but I had a few broken pairs. On the upside they are light and work well in mud. Pass on these. These also eff up the bottom of shoes unless you use the protector plate thingy.
Speedplay Frogs are an oddball here in that they do not use spring tension to hold your foot. There is a mechanical stop that keeps your foot held in until you twist it about 20 degrees to release. I can't comment on durability since I only rode them twice before returning them but they look weak and frail. I didn't like the feel of the Frogs at all. It is tough to tell when you are clicked in or out since there is very little tactile feedback, this is a bad thing on anything technical. I also hated the free float but many love it. Probably decent pedals and worth a shot if you need tons of float for your knees or some other biomechanical wonkiness going on.
Good old Shimano SPDs. I have used these the past five years and they seem as close to perfect as an MTB pedals can get. They have a small amount of free float side to side and a wide range of tension adjustment. You can fine tune the angle the cleat sits on the shoe side to side and also on a rotational axis. I broke a set of XTRs years ago but the warranty replacements are going strong. All the Shimano pedals I own have been insanely durable through rock strikes, mud, whatever. My favorite model is the M540, one up the ladder from the bargain M520. I like the feel better than the XTRs and they are just as durable while being pretty cheap. $50 bucks or so most places.
There are some oddballs out there like Bebops and Wellgos that I missed I know, but this should cover the major stuff out there. I'm sure plenty disagree with me on this but I'm sticking to my guns and my SPDs. Good luck to the rest of you searching for that perfect pedal. Try some Shimanos, they are pretty damn good.