Agree with all of the above, although actually I think he may have less of an impact on the pitch than we think, but time will tell (if it happens anyway).
I think it will generally raise the profile of the club, which is a hard thing to quantify, but it will raise the bar in terms of perception and helping to attract other players etc. You would like to think we could get the odd 30,000 crowd in pre-season and with general interest in Welsh football rising, people would want to interview Bale and by definition that would help City.
Unless we were gonna pay obscene wages and he subsequently failed miserably, then I can so nothing but benefits on and off the pitch