The fact that imbalance dragons is that they are multiclassed the D&D (and most other games) way.But all in all there are some very nifty abilities dragons have, that bipeds never will. Again, depending on your view/play style depends on how useful they are
They get several more or less working (read some dragon threads to discover that some of our key skills have been bugged for a year and will be till next push on Blight), several "toy" and "show up" abilities and spells that "look cool" (but no mob is impressed by a cool dragons - they first kill, then ask).
And most of all, their multiclass is subtractive.
That is, the fact of having several "classes" or a mix of etherogeneous abilities is kept balanced by them being watered down to keep the overall power lower.
It's almost like a maxed dragon was a level 80 warrior 80 druid 80 mage and some level cleric that overall has a rating of 100 (numbers being just figures - of course I'd kill to be rating 100 and have those classes - I'd own everything [;)]). Even the fighting abilities, very themey, stop at level 70.
On the contrary, the game balance and mechanics demand for a an additive multiclassing. Which is not bad per se, since the game is made with it in mind and so it fits good, it's just that who has the subtractive model lives a different and lesser "dimension".
Somehow a dragon is confined to level 100 rating and below, others can freely go 100 and beyond, so of course they'll beat the hell of mobs. And of course a guy rating 140 will (and should be) tearing thru 20 level lower or more mobs, expecially the weakies like fyakkis and spiders.
Meanwhile, to continue witha (newer) D&D analogy, dragons did not get prestige skills, and it makes them even more disadvantaged.
A situation I hope ARoP will at least attempt to offset a bit.