TL;DR summary: Grid and Healbot are the raid frame replacements used by many if not most raiding healers. They're optimized for healing and/or decursing. Choosing to use one or the other is a matter of personal taste, not feature set.
Any unit frame addon would have the advantage of being designed to be scalable, configurable, moveable, hideable, and the other "ables" that go with being a value-added replacement for in-game functionality. At the same time, they're relatively heavyweight, and with the configurability comes a bunch of configuration options to navigate to get what you really want. I use XPerl, not so much for healing, as to replace the standard player, target, and party frames so that I can control them as well as the raid frames.
For healing, you can use the default raid frames or a replacement like XPerl (click vs. mouseover is a separate, though related, issue). Or you can use one of two basically equivalent raid frame packages targeted at healers, Grid or Healbot. Both of these have the advantage of being streamlined to minimize/eliminate information healers don't care so much about and emphasize the information - health status/lost, (dispellable) debuffs, (my) buffs e.g. beacon target, who has aggro, incoming heals, etc.
What Healbot gives you over the default is that it's optimized for healing - you don't need macros (although they certainly work), but can set up your mouse clicks to automatically cast certain heals/decurses/etc. on the target you're clicking. Healbot has a bad rap from the days of vanilla, when addons were allowed to be smarter than they are today, and it made some of the decisions (downranking a good example) that healers themselves must make now (downranking not a good example). Similar to decursive, which back in vanilla was apparently a "one-stop shop" - healing wasn't even a glorified whack-a-mole with such intelligent tools. Now that lua is much more tightly constrained as to what addons/macros can and cannot do, healbot is just a front end, and has a lot of proponents - I'm the only healer in my guild who doesn't use either the default raid frames or Healbot. The only issue I can remember lately is that some people had problems during the early days of "incoming heal" communication - they seemed to see that healbot would read others' incoming heals but not write its own; it is controversial as to whether this ever happened, but it definitely is not happening now - Healbot plays well with the other children.
The other major player is Grid, which is what I use. It is even more stripped-down than Healbot, at least in the base package. It is just a raid frame for healers that displays the raid as, well, a grid of boxes for each raider that give status information. It comes packaged with components for detecting buffs/debuffs/boss abilities that give the package basically the same display capability as Healbot. What it doesn't do out of the box is any kind of click mapping - it's just a raid frame. So it's generally referred to along with another venerable add-on, called Clique, that just - wait for it - maps spells to mouse clicks on a certain type of frame (i.e. you can configure it to only map when you're over a grid cell, but not when you're mousing over a target in the field of view). Grid works a treat with mouseover macros, as this was its original intent.
The impression that I get is that Healbot is a bit easier to get running, while Grid can be tweaked a bit more to provide slightly more information. But basically equivalent.
Also, as long as communications are being mentioned, shout out to PallyPower, which coordinates all paladins in the raid as to greater/lesser blessings - and in the most recent version, auras (which I'm not using until I find an easy way to switch on the fly). It shows who has the optional blessings (kings, sanctuary) and who has the improved versions of the baseline blessings (it shows the improved versions of auras too) and allows any paladin to assign all blessings for the entire raid. It even covers the case where, for example, there are paladins of multiple specs around and the prot wants to give sanctuary, the ret kings, and the holy has to give wisdom to herself and might to the other two (she gives greater might to the paladin class and overwrites that with lesser wisdom targeted on self) - the interface makes this very easy. It even displays the number of symbols of kings that everybody has, and allows you to toggle righteous fury from the same interface, saving an actionbar button. The developer seems to be listening to the community as a lot of these features are new or fairly new, and the only major thing on the wish list is to streamline the inter-raid communication it uses to make sure it affects people's lag as little as possible. But even so, if your guild is the type that mandates raid addons (e.g. boss mod and threat meter), this probably should go on the list.