Ask ten paladins what the best way something should be done, and odds are you'll get at least seven different answers. I'm sure, mathematically, there is one theoretically "right" answer, but then you have to factor in peoples' playstyle, reaction time, raid comp, gear levels, overall raid skill, overall heal team ability, etc. So I usually answer this kind of question with "start with the generally held consensus of what is optimal, then fine tune it to fit you."
Having said that, here's my profile: I'm a twitch healer who favors small, fast heals and puts a premium on burst healing. Unfortunately, I've not been able to truly play that style for all of Pandaland, but the closest I've been able to come so far is this:
- Spirit soft cap of 10-12K (depending on gear level)
- Reforge to SPI or MAS
- Gem red pure INT; gem yellow INT/MAS; gem blue INT/SPI
- Enchant INT or MAS wherever possible
I know this runs counter to what many healers do, which is stack SPI however high they can get it, and which is what I did for a long time this xpac. But it occurred to me that the spells I used the most in crisis situations (HS, Prism, EF, FoL, Rad) were basically unaffected by SPI. (HS & Prism are cheap; EF is mana-free; FoL & Rad are expensive to the point that a couple thousand more SPI wasn't really going to get me that mana back vs. trinket/plea/pot/tide). Furthermore, since they are all instants or fast casts, HAS didn't really factor into the equation (except for Rad). So the end result was going for as high an INT as I can possibly muster without completely gutting the other stats, which has the effect of my core spells hitting like trucks. And since they're fast or instant, that constitutes my heavy burst healing.
Now, I'm sure someone will kindly come along and call me retarded and a baddie for using this loadout - *shrugs* - but this is what I had to do to make it work for me. I hope this gives you at least some food for thought.
If it helps, I use my CDs exclusively for raid-wide burst healing:
- Avenger: HS->LoD->Rad->LoD->HS->LoD (etc; might slip in a FoL on Beacon)
- Favor: Rad->HS->LoD->Rad->HS->LoD (etc; HAS buff from Favor helps with Rad spamming; yes those are 2pt LoDs by intent)
- Wrath: same as Favor, just a little slower and hits a little harder
- GoAK: FoL/HS/EF->Rad->Rad->LoD->FoL/HS/EF->Rad->Rad->LoD (etc; make full use of the stacking HAS buff)
- Heroism: same as Favor, if situation involves heavy raid-wide damage
Probably also should've said that the above constitutes my burst healing strategy, not my overall strategy. Overall, I spam Holy Light as much as possible, due to its 100% transference to Beacon, and because - starting at around ~11K SPI - a rotation of HL->HL->HS->[EF] becomes practically mana-free and even allows for replenishment if you're spacing them out enough to get the full effect of the cast (and not snipe other heals or overwrite a ticking HoT).
While I would certainly love more HAS to make the HLs cast faster, the reality is that the extra 0.2-0.4 seconds saved per cast doesn't really matter in a controlled damage situation; if the situation transitions to a burst healing situation, I then abandon HL and switch to the above strategy.