Trying not to repeat my above post, the whole argument against alacrity is it's negative effect on resource management when bursting continuously. Whilst resource management is a large part of healing for mercs et al it in large part comes down to the player, boss fight and raiding roll.
Now I'm no math geek and I'm not going to give you spread sheets and models. Arguably our rotation, mine at least, tends to be:
- kolto shell (for healing buff)
- kolto missile (for healing buff)
- HS (for armour buff/RS buff/HOT)
- then wait (fire a free rapid shot) .... YES WAIT ...
Why you ask? Well the answer is so simple that I'm sure everyone knows already, the tank is almost certainly at 100% hp. The next bit, the whole fight in fact, is now reactionary and, for me personally, this is where alacrity and power shine above surge and crit
Cast speed (alacrity) allows the caster to react to damage faster, on average 0.4 seconds faster because of increased cast speed. This reduces the chance another healer has picked up the heal in your absence, spike damage on the tank and allows you more chance to throw a free rapid shot in post HS, kolto shell/missile, or RS. Stable, quick reactionary healing mitigates the need for big burst heals or having to spam several abilities in quick succession and rapid shots become a top off ability that replaces RS/HS.
Power allows a more sustained throughput over crit and surge, and if healers / dps are good the need for large 6k heals are vastly mitigated.
It comes down to you at the end of the day. You can choose ignore my experiences over you own, try out alacrity / power and see how it goes or voice another opinion. I'm just giving you my experiences and not cleaver models based on simulated scenarios.
N/b - I wasn't trying to be overly critical of modelling, it helps formulate a theoretical picture but often it's practical application can be different.
Regards
Jadenn