I think there is a lotof b******s written about fitting tubs. I read oodles of stuff recommending this that and t'other before finally settling down to Mavic mastic one. I was assured by many respondents that using glue was horribly messy and diificult to fit. Well, it aint.
I fitted a pair of Vittoria tubs using said mastic easily and without drama and having never fitted tubs before in my existence. As long as you let the glue dry in accordance with recommendations, you will not end up with the whole of your bike and you smeared with the stuff. Neither will you find you cannot re-position your tyre after applying said glue. And you will find that tubs ride in a way you would love tyres to ride. They are simply superb. The comfort is as nothing I have experienced with tyres.
Go forth and fit tubs. You will not be disappointed.