When Cataclysm launched there were some real issues with Ret paladin scaling. In particular Mastery was an absolutely terrible stat, as shown by the weights below.
Str - 204
Haste - 80
Crit - 74
Mastery - 38
On the PTR Mastery has been changed to add a substantial % of Crusader Strike and Templar's Verdict damage as holy damage and no longer to give additional attacks. This is a major improvement in two ways and a major annoyance in one way. The improvements are twofold: First, paladins no longer generate Holy Power (HP) in single chunks. That was a big problem where due to the delay of displaying HP we would often go over the 3 HP cap and would lose HP by doing so. It also made the rotation feel really manic and shaky because every single strike had a large % change to change what the next strike should be and that % chance was only resolved halfway through the GCD. Now all HP is either gained via CS in an entirely predictable fashion or comes in 3 HP chunks so the rotation is much smoother. We can actually plan attacks a few seconds ahead and although we still have to react to multiple procs the interruptions will be less frequent. The second improvement is simply in overall damage; Mastery is a much better stat now and Ret damage is improved significantly overall, in the neighborhood of 11%. The new weights look as follows:
Str - 225
Haste - 80
Crit - 76
Mastery - 94
The major annoyance is that I, like most good Ret paladins, have been collecting haste/crit gear. I deliberately avoided anything with Mastery on it to try to maximize my damage and now I need to go out and acquire Mastery gear instead. If Mastery had been comparable to the other stats this wouldn't be an issue of course but it is significantly better, enough so that I will definitely want all of my pieces to have Mastery on them. Of course I shouldn't complain too much since the numbers are *much* more in line now than before and getting a general dps buff is pretty great too but it is frustrating to have to do a complete about face, especially when I need to collect Mastery gear during the period where Mastery is still junk. It reminds me a bit of the problem in Wrath where Survival hunters got a big buff and suddenly every raiding hunter had to swap specs to optimize their damage. GC said that they felt like this was a big error: Better to buff underpowered things very gently so players don't feel like they have to change their gear/spec/style en masse all of a sudden. Having the worst thing suddenly become the best thing means that you get a lot of people ticked off.
Initially I felt like Ret paladins were heinously underpowered in Cataclysm. I was bottom of the damage meters consistently and there seemed to be nothing I could do about it. Last night in our raid I was #2 though, and that on fights that really favour ranged damage in a lot of ways. I just don't know what is up with that; I have acquired a completely broken trinket and got a few upgrades but there is just no way I should be improving by 50% based on those few upgrades I acquired. I wonder if there are some changes that have been hotfixed in that I just don't know about.