To be honest, after having it around for 2 ages now, playing attacker - an orc and a dwarf - and implementing strategies as a leader, i think the new overpop mechanic actually requires for you to plan more strategically and utilize buildings or race/pers combos better. I mean the old attacker gameplay was essentially armies in armies out and you're good (a bit more to it but we're talking basics here). With the new mechanic, per hit gains mitigation (GS), prevention of intel plus the utilization of LL (mtpa, mwpa and TDs) and massive attack time reduction (rax or racial) are all viable strategies. At the moment, i think those three strategies are not balanced as well as what they could be, but being that i played dwarf i could use them in combination with the usual stacking of huge attacking power. I think that for this mechanic to work well those strategies for mitigation should be tuned into attacker personalities or races.

But as the question posed by the OP was whether it was good or not.. i dont know. I think its different and in some ways that's better even if it ruffles feathers. I also think that with this mechanic, Undead could return as a race and not be overpowered (but thats a different discussion). I think simply say orc and avian have the advantage is not quite correct. There is also Tact and gains science, as well as to a lesser degree BE, Tools sci and Thievery sci. I think i like the mechanic... but i also think that other parts of the game work against its potential, and that the strategies for mitigation (not just soldier aid) should be explored a little bit more before the whole thing is rolled back.