Pavel,
I'm still real happy with my Shimano Click'r T-400 double-sided SPD pedals. The same pedal in an SPD/platform combo is the T-420 pictured here:
http://www.bike24.com/p259550.html You can read about my journey to find them here:
http://thorncyclesforum.co.uk/index.php?topic=6943.0Unlike other SPD pedals, the return springs offer 60% less resistance to release -- and I have mine turned to minimum at that. I've now put upwards of 18,000km/11,000mi on mine and have never (not once!) had them release in any "drive" situation, yet they release almost instantly when I wish in any direction thanks to Shimano multi-release cleats. It is like having neodymium magnets attached to my shoe soles instead of cleats. Best of all, I have none of the debilitating knee pain I got from virtually every other brand/model of clipless pedal.
The bearings use loose balls and can be serviced by pulling the "axle cassette". Regreasing is easy and takes seconds, assuming you've bought the cheap plastic tool required to undo the works.
Shimano's Click'R series is aimed at novices and the indoor spinning market, but I have found them durable and well-sealed for my use. The guts are the same as the ever-popular Shimano M-324, and the T-700 series offer XT-level innards, but of course they lack wrench flats and so were out of contention for me (they were also no smoother in my tests). The goofy-looking plastic surround has proven durable and is a nice place to carry fore-aft pedal reflectors which are noticeable to closing car traffic at night. Oddly, my T-400s tend to flip horizontally when not in use, but with double-sided entry, it has not been a problem. If I can find them to stand on, I'm in.
My other bikes use SunTour Superbe Pro road quill pedals and I use them with one of my ancient pairs (I have several pairs in back-stock) of Detto Pietro Article 74 road cleats from waaaay back in the day. I use them with toe clips and straps. Most of the toe clips are CatEye nylon, having broken numerous KKT/Kyojuto, MKS/Mikashima, and Christophe clips. The CatEyes just keep going, no matter how hot or cold. I take the XXL size for my size 45 Dettos, as the CatEyes are sized small. The SunTour Superbe Pro pedals have a unique cage spacing so the shoes used on them won't work on other pedals without a cleat adjustment. The pedals do hang nicely for entry and there is a "flip-tab" at the rear. They run forever on extremely smooth sealed bearings (deep-groove Conrad type *and* roller-bearings) and so are self-orienting due to gravity and therefore offer consistent entry. One pair of mine has well over 32,000 miles of service and is still as new without any roughness or excessive play, though they have never been serviced. Another pair is catching up at 28,000+ miles. I have...um, six pair. Love 'em.
I have used PowerGrips, but found them lacking in some ways. The material is quite stiff, and if crimped tends to stay deformed (a person *will* step on them at least once). If you use them with different shoes or as your shoes wear, they will need to be adjusted. Adjustments were not so fine as I wished, nor as handy as pulling up a toe-strap end. I also found they ultimately put a lot of uncomfortable pressure on my outer metatarsal heads (the outside ball-of-foot) and that hurt after riding awhile.
As with all these things, it is an individual choice and what works for one person often won't for another. I'm a spinner, and need to be firmly attached to the pedal to make that work at high revs. More efficient for me also as I can pull back and up and also kick forward and not just push down. A masher has many more options and tends to do better with platform pedals than a spinner can.
All the best,
Dan.