Is, in my experience, relatively rare, at least by the time you get to hero and the characters that utilize such a tactic tend to be one trick ponies.

Now, when coming up the ranks it's clearly more common, but largely because most characters simply don't have enough HP to withstand ten rounds of lag against the kind of foe who is capable of carrying it out (and we're really only talking about three classes here.)

Because of that, because it's part of the gauntlet (or gantlet if you prefer) that must be run by character who will be powerful at hero, I don't have a problem with it.

Once you get to hero, who's really permalagging? Transmuters maybe, certain ranger builds, Greeting giants, but it's not very common.

All in all, I think that there are things that would serve the playerbase much better in terms of funstick than changing up a lag system that, while not perfect, is far from being broken.