As you know, I've just done this and plumped for Zenfolio. I don't know of any better UK-centric outfits, so I'll be very interested to hear if anyone has experience with other fulfillment options.
As far as their cut goes, I think it's pretty fair actually. Given the massive amount of work that I had stuffing envelopes and dealing with queries post-LEL, their cut seems quite reasonable. I'm definitely going to try and avoid that kind of workload again.
That said, for low volume fine art work where presentation and the personal touch is everything, self-fulfillment might still have a lot to be said for it.