I bought some Egrons on my full suspension Niner (based on a post last year by BwPA) and have been loving them. I have always used bar ends, because I like the additional position for roads, climbing on trails, and particularly for standing. I got the extended bar ends because the shorter straight ones tend to catch bushes. I use wide bars, and the longer curved in extensions allow me to go through brush, thistle, and branches without snagging, and with protected hands.
I really like the palm support, but an unanticipated bonus was that they also support you palms when using the extensions, which was always the more uncomfortable position with regular grips. The angle of the grips and the extensions can be adjusted independently, and I think the key is to get the grips rotated to the correct position so that the palm is just lightly pressured during normal riding. IMO they help climbing, descending, and on the flats. The long extension C3 model was about $60, which seems like a lot, but is really not much more than good grips and bar ends, and way more comfortable. I got the Gripshift specific model, and the work well with my shifters.
Our local shop has some sm and lg demo Ergon grips and told me that everyone who tried them bought a pair.
Edited by mudfoot - 7/2/10 at 1:34pm