You make a good point on procs, but I can only go by the data mined from my extensive research.
Seriously tho, Hail being up so often does a lot for the -resist. Beam and Seismic just don't compare overall, imo. Water in particular is solid, but I think DP has it beat.
But Time is doing the heavy lifting, it does virtually everything. Slowed response with Achilles Heel in a high rech build is high end -res (-50 to -70 on 16 targets in a 25' ? Yes please). -Regen is certainly nice against hard targets, but everyone has the dagger so it's not a big deal anymore. Not enough to make up for everything else Time does.