I don't think empowered characters should be stronger than unempowered characters. Getting empowered isn't that hard to the subset of people who are going to make a class look overpowered anyway.

As far as exp penalty goes, I was thinking more alone the lines of 300xp.

Also, while druids are cyclic, they do, as far as I can tell, have something extremely powerful no matter what the cycle.

To me, the thing that makes druids seem a little power-heavy is that they can lag, do big damage, and have good damage resistance all at the same time. Paladins, for example, can't do the lagging all that well. Also, the combination of druid abilities just meshes a little too well for my liking. For example, when caught in briars (providing the lag) you could use a wand to recall, perhaps. Except that sunray will blind you while doing huge damage too.

It isn't much comfort to know that the druid is going to be fireseeding me during a new moon instead of sunraying me. Actually it is, but even fireseeds is quite horrific if you are stuck in some briars.

I actually have the phase of the moon in my prompt even though I don't play druids, just so that I know when they are ubernasty instead of just extranasty. Admittedly I also have indoors/outdoors and wilderness/civilised in my prompt too to cope with other classes, but still.

I'd also add that my view isn't colored by dying to druids. I think the only druid to ever have killed me was Amora (who did it twice) before the bug in her herbs got fixed and also Airael (which was intentional on my part). I have this view both because of what some druid players have said themselves, and because of what I've seen them do to other people. I have killed a few druids, but only because I've timed the attack for when they are badly hurt and/or distracted in the first place, and that will kill any class.