Primordius is a horrible fight to judge output on because of the variability of the buffs. If you get 4 mastery you're going through the roof, 4 stats or 4 crit? Meh.
I was bitching last night that my own gemming doesn't even make sense to me because of trying to balance spirit vs. mastery so I end up with goofy stuff all over. There a ton on conflicting opinions as to the right level of spirit and we just don't all agree. I don't know if there's a real difference with spirit requirements in 10 vs. 25. It doesn't seem like there should be but I'm down to 15k and a little nervous about it while I hear other people say that they're fine with 12 or 13k and I have friends that are cruising at 16k+ and using spirit food/flasks still.
If you happen to notice mana levels and all your healers are at 100% all the time they you might want to address it but if they're using the mana they have then they're probably right.
The best anyone will be able to tell you is if your pally is doing things mechanically correctly. If you want sort of an overview, check the link in my sig.