Pretty much those reasons plus I (as DM) don't have to track it. We started with the standard initiative and switched a few months ago. My group, as they'll readily admit, are not very tactical but they have been noticeable more so since we switched. Combats seem like they are speedier and feel a little more "satisfying" than when everyone was pretty much taking individual turns.
The rogue in the group has the Assassin archetype and so we introduced a slight tweak to the group initiative (I didn't come up with this...I read something along these lines somewhere). Each PC and each group of monsters roll initiative. Any PC that beats the highest monster group goes first in whatever order they want (with the rogue getting her Assassinate if she goes), then the highest monster group goes, then ALL of the PCs go, then ALL of the monsters go, and so on. It kind of lets the fastest of the fast get in a first blow and then all of the benefits of the group initiative. It does mean that some PCs (or monsters) might get an extra action in at the beginning but we're a pretty team oriented group so that doesn't really bother us.