/snip I've always preferred to use groups of foes (which bizarrely I now get told I couldn't do with 3e, and yet somehow I did it anyway) so admittedly I made the situation more difficult than it would be if I was just throwing single monsters at the PCs (since all of the enemies are taking advantage of the buffs).
(and really, if a creature has an at-will spell-like ability that provides a buff - include the effects of that in the creature's stats!)
Oh, sure, you could do it in 3e. But it required a huge amount of work and pretty much every module designer out there realized that it's incredibly difficult to keep balanced. Either the encounters are cake or they steam roll the PC's.
Granted, using classed monsters would help here IMO. Keeps the individual creatures on the weak end of the CR, so adding a few (or more than a few) to the mix won't make a huge difference.
I think where you'll see a huge difference is if you try to use standard monsters in large groups. After about four, maybe five monsters, you're flying in the dark as to how the encounter will roll out.
One of the most egregious examples of this I saw was in the World's Largest Dungeon. In one of the highest level areas, they built up the EL by using large groups of formian workers, in another they used basic Derro. The party just walked all over the encounters. Didn't even break a sweat. Waded through armies of these guys and didn't even bother with spells. I think the wizard was using daggers and still killing every round.
Total, complete let down.
So, Spatula, yes, you are right, you can do it. However, it is not easy and it can fail spectacularly very quickly.
On a side note - the reason the argument about stat blocks morphed is because the original comment was somewhat unclear. Why did Rounser claim that there was a need for software to write NPC stat blocks? IMO, the need comes from the fact that stat blocks are really, really hard to write.
Raven Crowking - someone questioned you about the amount of prep time it takes in 3e? I hope that wasn't an allusion to me, because as far as I know, I've always said that 3e takes too long to prep and that's been the prevailing opinion around here for a long time.