I own one. It's currently my only head, although I also have a Traynor YBA-200A (200w, all-tube) on ongoing rental.
The ENX-260 has great tone and is small and compact. It's powerful for it's size, and when paired with a good cabinet it can move a lot of air, but I would be hesitant to gig with it.
I plan to keep it as my practice/studio/backup/guitar amp, but I'm looking to replace it for rehearsals and gigging. The reason I'm hesitant to gig mine is that it has several limited stages - it has an input limiter, an EQ section limiter, and an output section limiter. All are non-defeatable. These limiters make terrible noises when they kick in and they do so pretty early - while I could coax reasonable rehearsal volumes out of the unit if I tried, I would hit the limiters at least a few times.
So yeah - a good solid little amp for practicing or recording. If I did acoustic or jazz work, I suspect it would be just fine for that. But although it can cut it for the hard-rock I play, it's a barely-there sort of thing. I just want more power out of the unit before the limiters kick in.
Definitely try one out if you can. The tone is great, there's just not quite enough power for me - but it might be enough for you.