I raid with all three of my 85s: Tree/Boomkin, Resto Shammy and DK tank and use the same basic ui for all 3. The main thing is I use a larger bottom bar and viewport like Ymer does and grid is always the center of it. It's easy to just set up different profiles for tank, heals & dps, 10 & 25 and just mix and match if something needs to be a little bigger or smaller.

The only thing I've noticed that needs changing (in my UI) is moving grid from off to the side to a more prominent position closer to center. I actually like it to the left of my character and slightly lower than the middle of my screen so I don't have to look up to see what's going on around me. I achieve this by simply unlocking grid and moving it where I want it when I heal and moving it back when I don't. The rest is powered by ElvUI, PowerAura, IceHUD, and DBM. If ElvUI allowed for the player and target frames to be configured as a HUD, I'd ditch IceHUD in a heartbeat.

I'm a raid healer (tree, pally, priest; baby shaman that will be... one day), and I use an all-in-one. The important part for me was putting Grid in the right place: I have it in the middle on the bottom of my screen, but I don't use a viewport or multiple rows of action bars, so it's very easy to see health bars without getting tunnel vision. I put all my action bars in a single line along the bottom of my screen, with an additional line on one side that has class buttons (pally auras, druid forms, hunter aspects). Then I use SUF and Quartz to put unit frames and cast bars around Grid so that I can see me, my target, focus, and pets, and their targets, with minimum eye movement. I use PowerAuras in the middle of the screen (around my toon) to keep track of important buffs and cooldowns. Omen and Skada go to the side, where I can see them if I need to but they don't get in my way. I find this works well for all classes and roles, because all my important information is always centrally located, so I don't have to switch addon profiles if I go from tree to boomkin, or get confused trying to find Grid when I play a pure DPS class. I do use different Grid profiles for each class, though, so I can see class-specific info. And I use a similar Clique setup on every healer: big heal, small heal, fast heal, rez, etc., are always bound to the same button. This helps when I haven't played a toon in a while because muscle memory does a lot of the work.