With respect to 'new universities' v traditional universities - I think you have to consider each university on its own merits, and place issues of funding, supervisor quality and department quality, above the general perceived reputation of the university.
That said, I would be wary of some new universities for two reasons:
(i) if you want a career in academia, having a CV of only 'new universities' may prevent you from achieving a post at an older uni (due to the academic snobbery amongst *some* quarters and disciplines i.e, Oxbridge recruits Oxbridge, UoL recruits UoL, red-bricks recruit red-bricks) - obviously this doesn't always happen, but it's not uncommon.
(ii) some new universities have staff with little or no research capabilities i.e. they used to be FE teachers, who in 1992 or later became lecturers. Sheffield Hallam is an established new university - so this probably won't apply.