I saw 'Think Floyd' about five years ago and they were absolutely excellent. They really nailed the sound and feel of the originals, whilst re-creating a concert experience, albeit on a smaller scale.
Well Gilmour's tone, whilst exceptional, isn't too difficult to re-create. Basically you have to have a nice Strat with a medium output, the right delay settings and most importantly, the right compressor and distortion/overdrive. I can get quite close with my Rocktron compressor and MXR Zakk Wyde, but for 'true' Gilmour (depending on the era) you want an MXR Dynacomp (at least) and a Fuzz Face (for up to 'Meddle'-era tones) or a Russian Big Muff for some of the slightly later work. Gilmour has actually used a number of compressors as well and uses several on a single concert depending on the sound he's after and often uses more than one at a time. I'm not an expert on Gilmour, but there are some good web resources on his tone.
http://tonefromheaven.com/ is probably the best resource I've come across.
. Of all the Gilmour I've heard, the best I've ever heard is the 'Live At Pompeii' film during the instrumental section of 'Echoes, Part 1'. He unleashes this guitar part that sounds absolutely seismic. Godly. It's magnificent.
I'd like to read that.
The thing is with Gilmour that people make incorrect assumptions about his processing. They assume he's running fairly clean and they also assume that he's running a reverb module. Both, very incorrect, he actually uses a lot more gain than people realise...
I was in a tribute band for a while and really came to not like it. I found it to constricting and also found that the musicians were more attune to be like their 'heroes' than actually doing something musical or original like playing Four Sticks with four sticks. think it could be a lot of fun if you don't take it too seriously. But I don't know that you'd go too far unless you took it too seriously,
I just got an ad this morning for a Def Leppard tribute band that is seeking a one armed drummer. It says "This is not a Joke."