Many a shaman will argue that haste is the new it stat for restoration shamans. Sure we get to cast faster which adds up to more HPS, but what we sacrifice is much more important than haste.
As I am currently geared, I have the following stats.
Mana while casting:588
These stats are un-buffed, with the exception of totems which I consider a 100% up-time self buff. I've often gotten remarks from raid leaders that my crit is high, my haste low, and my mana regeneration at a good spot. I may never say anything, but I've never agreed with that statement. The reason my crit is so high is because the gear I wear is heavily stacked with crit, so nothing I can do about that. And honestly, crit is an amazing stat for shamans. We get mana back on critical heals, improving out longevity, and a crit heal can be the difference between a dead tank and a live one. My haste isn't low because shamans only need haste in one scenario: Heavy raid damage and Chain Heal spam. My guild runs with three healers, which means I am not overly taxed in AoE heavy fights. And as for my mp5, I would like to have it higher, but it isn't something that effects me unless I am spamming constantly.
I know several shaman healers that have an upwards of 800 haste, a number that to me is incredibly, and abnormally high. These shamans are great healers in their own right, easily out gearing me and out playing in my opinion. But I can't help but think that the 5% crit that they are missing compared to me would greatly help their healing. More often than not, my mp5 is also much higher,(The shamans in question have Solace of the Fallen/Defeated, so this really doesn't apply as it is a mp5 trinket).
For any starting restoration shaman, I would highly recommend gemming for spell power and Int as these are the most important stats for healing heroics/Naxx. Once on to harder content like Ulduar, I would suggest Int/mp5 gems,Int/SP or Int/haste. Once you know your class inside and out, and have a firm grasp on where most of your healing comes from, you can change your gems and enchants accordingly to fit the play style that you enjoy and are best at. Never let someone force you to play in a way that you feel is inferior or wrong. If someone tries, explain why you chose to gear as you did, and if they don't like it, so what, it isn't their character to screw around with. If this person happens to be a raid leader and doesn't want to listen to what you are telling him, I would suggest moving on as the atmosphere is obviously wrong for you.
This informative delve into the art of shamans is brought to you by: Shamans- WE GOT MUTHA FUCKIN HEALIN LAZAHZ.
Also, the Association of Moonkin Haters-Purple vertical lasers are offensive to shamans everywhere.