Not my experience, at least in SL. Season 1 was harder than Season 4 because reaching enough haste to get 100% uptime on SotR was really difficult early on and really easy later.
Everyone gets the exact same benefit from Vers. The difference in stat weights is about the relative value from one stat to the next. But if you haste and mastery are high enough to suffer from DR, at a certain point, the value of Vers goes up because the benefit of X amount of vers would exceed the benefit from the same amount of haste or master. The actual benefit of Vers though, point for point, is identical between every class and spec.