Grid is just like normal raid frames, in terms of how you interact with it with your mouse.
If you like to heal by clicking, make your spells Mouseover macros and they'll work just like they would with xperl/pitbull/wow ui raid frames.
I like Grid because it's not an eye sore to look at, and you can customize it for healing purposes much more than you can just about any other raid frame addon. I'm not extensively experienced with healbot, but I did try it out for a few raids, and xperl ended up attracting me more, and now I'm using Grid.
Really, the best advice I can give is to simply DL/install Grid, and follow this guide to set it up, and then spend some time tweaking it the way you want. Do some BGs, and give it the honest time you would have given Healbot and make the decision for yourself. I can tell you that there is only 1 latency issue I've had and that's the switch of Aggro. The icon takes a second to switch on the Grid, but everything else is spot on. This doesn't effect me though because I'm perfectly aware of when someone else has aggro without it.
Just about any addon is worth giving a real shot.

