Yesterday we had a couple posters in the comments section getting into a minor kerfluffle (addendum: must use kerfluffle in real life speech 3 times today) about which glyphs to use. Before Ulduar, I was rocking the glyph of Maul, Frenzied Regeneration and Rip. Yeah, Rip - it meant I could do decent DPS while in tank spec and tank gear. Then a guildie got Survival Instincts, and after that I decided that I was tired of breaking CC or even worrying about it much, so I got Growl.
And this caused much consternation.
Except...I don't see why. In 3.1, glyphs can be used without a lexicon of power - meaning that any time you want to replace a glyph outside of combat, you can. There's no need to decide on 3 glyphs at any given moment; they're totally mutable. They're also really cheap to make. The Growl and Survival Instinct glyphs comes quickly from northrend herbs. Maul glyphs come from STV herbs. Frenzied Regen comes from easy Outland herbs. Rip comes from Feralas/EPL herbs.
Most of the time, one stack of herbs will give anywhere from 5-10 inks, which will make 2-4 glyphs. So for a full stack of 20 glyphs of SI, you're looking at 10 stacks of northrend herbs, or around 200g. And that's the worst of the lot; you should be able to get a ton of Maul glyphs for far cheaper.
So instead of looking at it by which are the best, perhaps the better way to look at it is by cost. In that case, you should keep SI and Growl around for a while, and swap Regen and Maul as your third glyph. That'd be optimal, but chances are that won't work most of the time; most of the time you'd want both SI and FR as your regular ones.
So it's down to growl and maul as your hot-swappable glyphs (at least most of the time).
For me, I was able to buy a stack of growl glyphs for 15g. Why? Because they're typically used to level up. So they're pretty cheap anyway. Furthermore, you're not looking at more than about 5g per glyph if you buy the mats, which means practically that you're going to swap them out what, every fight at most? Which means if you're having a good raiding night you'll spend about 40g in mats if you swap every fight.
And unlike food, they last for as long as you want.
That's pretty cheap to me, honestly, and adds a lot of versatility. Are you going to tank and DPS in the same fight? Go swap out that FR glyph for rip. Have a manglebot for a given fight? Swap that mangle glyph for SR (this one is huge for me, honestly - it's like a 2% DPS boost) Need to make those taunts count on Kologarn or Auriaya? Get growl. Need maul on one target because of CC on the hallway of Thorim? Swap out Maul. Going to do the arena? Swap it back.
This honestly is really applicable to all sorts of specs. I've been getting more familiar with priest healing thanks to my wife, and she's fighting between Flash Heal, Renew, Guardian Spirit, Prayer of Healing, Circle of Healing and Power Word : Shield. But why fight? Why not pick one or two that are going to be regulars (Flash heal and CoH, most like) and then swap out as needed for fights? Guardian spirit's glyph is useless if you're not healing on a single target all that often in a fight, but if there's a lot of raid damage PoH may be a life saver. Etc, etc.
Honestly, this is kind of a revolutionary thought for me. I'd never thought of glyphs as consumables before this.
The disadvantage is that you'll be carrying a few stacks of glyphs, which means more inventory. Such is the life for a druid. And it won't always be worth that much to change; a lot of times which glyph you have won't really matter for a given fight, and you won't have to change a thing.
So glyphs aren't the new talents. They're the new flasks. Get friendly with your local inscriptionist and give yourself some versatility.