What about Paladins "Flash of light" if you have enought +heal you can cant 2,5k heals so you have mana "with the proper use of pots" to cast unstopable until the end of the fight.

with the 1,5 sec heal you may be the best healer on the raid so the +heal is not useless

Learn to Dps
Learn to heal
Learn to Tank

and then make comments about the raiding stats who someone needs

I don't know about priests since you only have one HoT, but as a druid bigger heals does at times does mean less healing, if I can pop a triple stack life bloom and and rej, even on some raid bosses (unless there is the unexpected spike damage) I can sit back and just pop a LB once every 6 seconds, and rej every 10 seconds.  Less +healing means I have to pop on regrowths to help keep the tank up more often.

850 to 900 hps just from 3 LBs is not that bad and about 1000 every 3 seconds from Rej is also not that bad, that works out to be about 1184 hps on the tank depending on damage in.

And since (from mostly spirit) i have about 320 to 350 (depending on raid buffs) mp5 while casting (have to love Intensity http://thottbot.com/s17108 I have well over 700 spirit in raids)

The only situation where I can say where mp5 is more important is for raid healers in SSC/TK/early BT/early Hyjal and that's just because raid damage is fairly minimal, but fairly frequent (Naj'entus aside). When you start to develop into later BT - partially Teron and more importantly Bloodboil, you'll need to switch the focus as a raid healer to more Healing/Haste. Mp5 just falls behind as you progress, because fights don't really get that much longer.