Personally, I'm a Time ATAC fan and have experience with many SPD versions as well, but I haven't used the Eggbeaters or other Crankbrothers pedals yet.
The Eggbeaters have a very open design and it looks like they shed mud and sand easily.
Shimano SPD and Time ATAC can be operated (engaged) from 2 sides (top and bottom), but you can get into your Eggbeaters from 4 sides!
Both features certainly are pro's.
Cons could be the small support surface and the bearing quality. I don't know if there were quality problems with Eggbeater bearings or if those problems belonged to Look 4x4, which were made by Look under Crankbrothers license.
Same as with other pedal systems and bike parts, there are several generations and ways of manufacturing (quality, price). It looks like I have a set of Eggbeater C pedals, but to be sure I have to do more research and disassemble the pedals.
Anyway, the pedal design and place in the history are interesting enough to try these pedals in the field and to be part of my collection.
