I have one (owned it since July 2014) – very happy with it – its comfortable, gets used most weekends, the storage area is well thought out & access to your gear in it is good. I use a 3 litre bladder in mine rather than the supplied one as I prefer to carry a bit more liquid. I’m 5’9″ if that helps.
I have previously owned a Hydrapak Outland (was never really big enough – you could carry water or tools, but not really both), Deuter Speedlite (decent pack – straps could have been a bit more comfortable) & a deuter speedbike (great pack, but a bit big for general trail riding) – The Evoc has been a good buy & I’d buy the same one again if I had the choice.