I was never a big fan of Grid, I found the squares too small to give me an idea of who it was that I was healing, I"m sure it's great I just never liked it.. I liked using sRaidFrames (as a note almost everything I list here, unless links are provided, are Ace2 addons) to give me general overview of the raid as a whole. I found
RDX.Cid which looked cool and promising but really wasn't plausible for anything larger than a 10 man raid. I really have yet to throw a lot of time into RDX so maybe I can fool with it a bit more.
I'm the primary healer in our 10 mans so I definitely use Main Tank frames and a set of Player Target frames provided by ORA2. I can for the most part ignore the rest of the raid and focus heals on tanks plus my priority list of targets.
Also, I found
Healbot Continued to be awesome. It needs some work to take into account the +healing my character has so that estimations aren't as far off but it's awesome for a 5 man run or even a 10 man. It needs a few other features like bar colouring when I need to disspell or abolish. As a shaman though it's just a totem if I remember correctly.
Frames are such a personal preference, if you like having the little grids so you can spot heal whomever needs it when they need it rather then needing to prioritize in your head based on name / class then Grid would probably be good for you, takes up less room which is always nice. I also have a Druid which I occasionally bring for off healing and DPS rather then my priest as a main healer (main healing is stressful!) and I actually just use a collection of player target frames to spot heal certain members to ease the pain of the main healers.
My 2 cents.