I find classes in 4e quite balanced, and even criticized classes like the runepriest look fun. So take the remainder of my post with a grain of salt.All that said, it's been an enjoyable class.
The common criticism, which I agree with, is that theAnd you either need to got for lots of rune feats or none.
The common criticism, which I agree with, is that thelatterformer is a trap. Runic feats encourage an "in for a penny, in for a pound" attitude. That's to say that if you take a couple, you might as well take them all, because they all improve each other. Unfortunately, there are a couple of decent runic feats, but most of them compare poorly to other feats, even when "augmented" by other runic feats. So, instead of having a bunch of really useful feats, you end up taking two somewhat useful feats and a bunch of useless ones to make the first two better. It's a trap that leads to poor character-building.
I know I'm straying from the topic here, but my feeling was that their racial power kinda made up for the lack of support: it's truly fantastic to regenerate, especially if you manage to keep your defenses high (and therefore have a round or two of being missed to regenerate during combat).I say, I wish I took a race with more feat support (longtooth shifter). I've got lots of useful, general feats, but very few that speak directly to being a runepriest or a shifter.
I know I'm straying from the topic here, but my feeling was that their racial power kinda made up for the lack of support: it's truly fantastic to regenerate, especially if you manage to keep your defenses high (and therefore have a round or two of being missed to regenerate during combat).