I had some older XT’s, the servo wave ones are supposedley even better. I had 4 years trouble free braking from them, they were great.
Like you, I fancied some hopes (newer style mini’s though) which I bought 2nd hand (great condition) at a good price. I’ve fitted them and used them twice, they arent as good as my 4 year old XT’s were. Perhaps I need to bed the pads in better, as I’ve only used them twice.
In my opinion, Hopes are very expensive for what they are, and everyone knows XT’s/SLX brakes are about the best you can get for near enough any money.
Also, my mate who rides downhill has some of the M4’s with those funny levers, and he’s had issues with them. I wouldnt bother if I were you.
I’ll probably keep the Hopes I have now and see if I can get them setup properly, for xc riding they feel just about ok though.