Crit does not have rating DRs- 600 crit will always give you 1% crit chance, going from 0%-over9000%. For dps value, it does have scaling DRs/soft caps, which will be of no concern to warriors/DKs (but is of concern to guardian druids, and potentialy monks)
---------- Post added 2013-06-26 at 05:56 AM ----------
Since when does Haste provide equivalent amounts of survivability compared to dodge/parry? It DOES provide significantly more dps, but will provide less overall survivability (1% haste will provide 1 extra DS per 100 DS used. At an average rate of around 10 DS/minute, it would take about 10 minutes to get 1 extra Death Strike. On the other hand, 1% dodge or parry will remove 1 melee attack per hundred attacks. Since boss attacks come in at most at 2.5 seconds, thats 1 damage removed from the table per 250 seconds, or less then every 5 minutes. Dodge/Parry is superior to Haste for mitigation. If my math is wrong, please correct)
Haste will prove LESS mitigation then expertise/hit soft capping does (7.5% for both) and THATS a 4% overall damage reduction from just going for dodge/parry secondaries (All DKs should go with mastery though).
Haste is trash for mitigation, but good for DPS.