still want to hear if there are other disadvantages to md2. . .
Loads.. the vertices wobble around ( separate from the animation ) and the surface won't light correctly. You'll get ugly patches on the models which are from not being lit correctly. You can't share animations between characters, you probably end up using a lot more memory, you have no bones so you can't attach weapons, and more importantly you can't "track" the positions of body parts so that the animations can be tuned to the environment.
About the only thing MD2 has going for it is that it's quite a bit faster than B3D format. You pay a high price for that though.