In reply to Gordonbp:
Fit is really important for gloves, especially if your going to use them for climbing. If you havn't already go to a shop and try loads of pairs on, dont be afraid to try on womens gloves aswell if you have smaller hands like me. Ideally you want as little 'deadspace' at the ends of the fingers as possible and a really thin layer over the palm for the best dexterity.
FWIW the three gloves you have mentioned, I find the ME guides fit the best but are probably the least warm of the three. Only thing that lets the ME guides down are they are an absolute pain to fix if you pull the pile liner out to dry it (top tip if you get them - never pull the pile liner out).
If its for more general mountaineering rather than climbing, dexterity probably isn't as vital and you might be better off with a nice pair of mitts which could double as belay mitts for climbing. Rab Baltoro's or ME randonee's might be worth a look aswell, try go for something thats warm whilst wet such as pile with softshell outers rather than the waterproof gore-tex variety.
Have a look through older threads on here aswell and you'll find a load of opinions, just a case of finding what works for you.