depends on the subject....
Most Constant (cheaper) sets are designed for the still life photo work some have the oomph to do portraits but few they are great in that as you work you can see what the effect is ...
Strobe Flash is more powerful and means you can use lower dof or higher in studio/portrait work none of the constant lighting set-ups i have seen will allow use outside in sunlight as they too weak even a decnt flashgun out performs them.
in summary if it still life you doing constant will do the trick nicely but flexibility and power wise strobe is always the way the decnt ones have modelling lights allowing the set-up to be seen then have the oomph when required.
by no means am i a pro or anything just what i have been readinf up on in fact three set-ups has been done in a mag i have read recently on constant light ing they all were too low powered next monnth they doing same with strobe ... yay
Mag is Advanced Photographer seems FINALLY we have a mag for those past regurgitated tests and so on