There is alot of debate whether or not glutamine really is worth supplementing. I have heard both sides, but I think the main thing is people aren't really going to "notice" the results of glutamine. It isn't like other supplements like creatine or so forth where you will see it working. I take it because it is hella cheap and my dosage is around 20 grams a day split between my two shakes. I have been working off the same 1000 gram container for a few months. The main reason I take it is because it supposedly helps prevent muscle loss which is important during cutting. A really general article on glutamine can be found here. Overall there are alot of people who believe it doesn't do anything, so its up to you. I probally won't be buying it again after this container is through.

I don't really know much about micronized glutamine but I figure that it would just be absorbed quicker and easier to digest like micronized creatine. Probally not worth the extra money for a supplement that many people don't believe in.

Your better off just buying the powder because the tabs are going to be more expensive and like you said, you will most likely have to chug down quite a few to get in the same amount as the powder dosage.