I like CL because it's another thing to worry about trade-offs in your gear. Do I wear the +3CL about robe and the +1 Int Wrist, or the +2CL + 10HP about robe and +1CL +1Wis wrist? How do I best optimize my CL to get it just to 30, without "wasting" slots by getting CL above 30? I dunno, but I find that stuff fun. I liked it to deciding between apply and -AC and resist etc for a tank.
I remember last wipe I had a legend black robe and a legend dk. What was each of these missing? The dk was missing "elite gear" like some crazy +10dr, lim dam, no bash, etc. The mage was missing the "big 4" spells. Maybe he was missing elite gear too but I have actually never really seen or heard of "elite mage gear" other than +all slot ring type things. I guess a mage no bash would be nice. I dunno. So in my opinion the correct comparison between tanks and mages is not CL vs. Dam Roll, but number of spells vs. Dam Roll. And what makes this interesting is that as a tank, yes you can DT and lose all your shinies, while as a mage you never lose your spells once you get them. So maybe it seems unfair to tanks. But on the other hand, the mage book race is SUCH a pain, and CR is often quite doable for tanks, that I dont think this is unfair at all to tanks at all. If anything it feels pretty balanced ... there were situations where the DK was more useful, and situations where the mage was more useful.
Anyway, just my experiences from the past wipe. And as I said in my first post, casting level was definitely one of the things that got me hooked on the game initially as a challenge to overcome and reason to explore and lore gear.