Eh, depending on class, s2 and s3 isn't bad. For a hunter s3 is actually a bit decent. For a rogue however, one's better off going with the tier sets. I've got both classes at 70... Deadly throw bonus for one thing, isn't exactly the most useful...
As to PvP; I'm not sure I'd call it exactly wellfare for the ali to suffer through AV post 2.3. Largely because it's a lot of frustration and taking it up the arse, to get less honor (without bonuses) then one could get from world PvP. I kid you not. I've seen AVs that have got about 11 honor points, for the time commitment. This was one for instance where the horde wiped the people as they were running down, before they ever got to the first GY, and the entire time was spent in defense, as they steamrolled to the end, and skipped much in rushing the end.
On the other hand, when my warrior was mining thorium to hit 300 BS (he now has like 342, and he had a lot of fel iron in bank already), I grabed a silithist and ran it back to the extractor. In no more then a minute I had like +19 honor, rather then +11. Given the time commitment, I just laughed at getting more honor running Silithist to extractor, then in doing an entire AV for alliance many of these recent days.
This said, it isn't always a matter of skill. My shamy will likely be a PvP char. In large measure, I don't like healing
Anyhow, I have 2 other chars (and soon my warrior will be 70), one of which has raided, another of which will begin this week. Sometimes it's a lil variety to do different things, on dif guys.