I owned a McNaught Phoenix for awhile so I'll try and give my honest opinion on them.
As far as fit/finish/quality/contruction etc. they're up there with the best of the best. The woods on mine were gorgeous and the quilted top really was something. When holding the guitar it felt very solid and there was no question I was holding a very fine quality instrument. So absolutely no worries in that department.
Tonewise I found the guitar to be on the darker side. Mine had a black korina body and neck with a quilted maple top and ebony fretboard. The body was also slightly chambered. It had a very full and warm/wooly tone. It was also a very resonant instrument. Though the guitar was very versatile, IMO it's bread and butter was smooth and buttery lead tones. I thought it lacked the punch and snap to excell at more aggressive rythym tones. This is not to say the McNaught can't get these tones, especially with the right pickups, I've just played other guitars better suited for those tones. I got some of the best clean and lead tones out of that thing.
I haven't played many Les Pauls but I found my Phoenix to be slightly darker. The Les Pauls I've played had a stronger midrange punch, while the Phoenix was warmer and sweeter.
Playability is my only beef with the McNaught. For me the combination of the heel, the way it hangs on a strap, it's ergonomics, and my slightly shorter fingers made the Phoenix virtually unplayable on the upper register. There are plenty of heels I can work around, the Phoenix I can't. That's also the reason I sold mine. It doesn't bother some, but in this instance I can't emphasize enough to play one first.
Whether or not it's worth it is up to you. It's definately as good or better than other guitars in that price range. Just got to play one and make sure it works for ya. Hope that helps.
