[Soleo]

Is it 6-max or 10-max game? I'd raise pot size about half of the time (or in NL instead of PL I like to raise $5 with this number of limpers) to try to get it heads-up or 3-way. Another half I'd just limp along to look for the set.
If you think that most of these limpers are very loose and will call your pot sized preflop raise with hands like KT, A5s then I'd limp 100%.
With passive players button raise will probably let you see flop and turn card (if you choose not to bet the flop).