So I finally dinged 90 last night and managed to get enough gear to just meet the requirement for heroics. I was originally shadow but my dps is abysmal right now. I then found disc healing to be quite fun when i was around 88. Now my question is whether healing heroics right at the gear requirement is manageable or if it is a lesson in frustration like it was in early cata. Or should i stay shadow until my gear is a bit better. I have been a healer for a lot of year so skill isnt an issue. Just sometimes the gear wall puts the group at a disadvantage at least from my point of view. Or makes it harder to compensate for bads if you want to look at it from that angle.
I'd say give it a shot to heal right away. Generally speaking the other peoples have gotten a bit of better understanding now of the heroic mechanics that when the big wave of 90s hit, days after xpac was released. That being said, you can't count on people carrying you, but as long as the rest of the group is not braindead they can understand if you have to take some mana breaks now and then.
I'll second that - go and do your best. The main problem with going immediately into healing with not-so-great gear is that our BiS trinket (Price of Progress from Darkmaster Gandling) has no normal version, or at least one that's useful at 90, while at 85, even though healing was much (read: MUCH) harder, at least you could get the good trinkets (Tears of Blood, Blood of Isiset, Eggshell, and what else have you). I started at 90 healing heroics as holy, and the only bosses I had trouble with are Jandice Barov (though this is mostly RNG-related) and Weaponmaster Xin.
5man heroics in mop remind me of wotlk, go in whatever gear you have and assuming your tank is actually a tank, your dps wont be taking naps in fire and you wont spam flash heal on renew, youll be perfectly fine.
I too used to suffer from the fear of healing at the beginning of every expansion. But seriously, MoP HCs are rediculously easy, not to mention most of the big hits are avoidable and by now most people know how to do that (but don't yet have the end of expansion godcomplex thinking they don't have to care about anything). The hardest part is just going; when you get past that, you should be more than fine.