According to EJ's, Mastery and crit are both superior to haste if you aren't near the haste break points. Most of the time if you can hit 2005 haste it is well worth it to get an extra tick of WG & efflorescence. If not, then it is probably worth reforging back to 916 haste where you get your 5th tick of rejuv (all assuming you have the 5% haste buff).
From EJs Resto Thread
Outside of haste breakpoints, your basic choice is between throughput stats (mastery and crit) and regen (Spirit). When it's not getting you extra HoT ticks, haste is your weakest stat since it doesn't benefit Rejuv and increases your mana consumption.
These points are a little more murky if you are doing 10mans as you end up casting a wider variety of spells than just rejuv, WG & lifebloom. This generally means that the haste will be worth a bit more due to its effect on HT, Regrowth & Nourish. Also, it often comes down to your healing style, so your mileage may vary :)
The Alchy trinket is fantastic for 2 reasons (1) With a red gem it gives you 30 Int more than any other 359 trinket! (2) It is one of only two 359 trinket with throughput stats (the other is the JP trinket, Soul Casket)- if you find yourself not having mana problems then the spirit/mana gain on the other trinkets is wasted. The other 359 trinkets are all pretty similar in strength and probably come down to personal preference. If I was an alchemist I would use the stone & the JP spirit trinket - the second purely because it is easy and cheap to get :) Edited, Aug 24th 2011 5:55am by RareBeast
____________________________RareTrevor - Feral/Resto
Other Rares - RareBertha (90 Mage), RareAgatha (90 Paladin), RareMildred (90 Warlock)
RareGretchen (85 Hunter), RareHelga (85 Shaman), RarePearl (74 Rogue), RareEileen (51 Warrior), RareDorothy (46 Priest)
Rarebeast-Feral Druid. and 9 other Level 80+ Rares