Originally Posted by
Schizoide
2H frost still has tons of downtime when you (correctly) stop delaying for Killing Machine. Pooling resources or delaying attacks has no effect on downtime at all, unless of course you cap resources. The only way to do anything about 2H frost's downtime is to spec Plague Leech, which every PvE DK in every spec should do, as it is essentially mandatory due to its damage delta over the two other options in that tier.
DW frost has much less downtime, particularly if you use the mastersimple priority, removing Obliterate entirely. Which you totally can do, again with very little performance impact.