Avenger Kit

Just wondering. I was looking around at a different character to play, and the Avenger kit in the Druid class attracted my attention. Normally I avoid Druids like the plague, but this one looked interesting.

I just completed Chap. 1 and found my Avenger to be great fun to play and very effective in the use of her shapechange (Spider, Salamander, etc), and the extra mage spells seem to make the character considerably more powerful than you're average druid.

But I worry about one thing: the Avenger seems very effective up to a point, but I wonder whether in the late stages of the game, when facing the real mean stuff whether the Avenger is no longer really effective? Anyone gone through with this kit? I really do like it so far...