i find that me being a Xmute specialist has been more profitable.
The reason being most of my elixers goto the guild for the 5-mans we do and the raiding. There for i find myself not selling much elixers. On the other hand people are always looking for primal might Xmutes or gem Xmutes and if it procs and you make an extra 1-4, thats pure profit!!
This is just my opinion, im sure others have their own opinions for different reasons.
ps- may take a while to make some money with Xmutes though, seeing it doesnt proc all too often.
I took master of transmutation and have not regretted it. The way I see it, farming mats for primal might or diamonds is FAR more painful than farming elixir herbs. That made the transmutation mastery a no brainer for me.
I picked Transumte, and totaly regret it, should have taken elixers or potions, i have had it for 3 mo, and it has proced 4 times, maybe I am just haveing bad luck.
I didnt get transmute because I was hoping for procs. With my luck I wont get any. I simply got very bored of running around and picking herbs. I prefere farming motes over herbs. Besides, the quest for transmute mastery is the easiest one.
Not like you cant still make your potions/flasks or whatever you want. And I wouldnt count on procs really.