Nothing like summoning 32 demons to gum up game for a while (Conjure lesser demon, at 8-9th level). That just seems like reckless spell design (which I assume is what they want feed back on). It is certainly possible to have clever ways for a good DM to handle it, but for many games it seems like handing people more then enough rope to hang themselves with. It's the sort of thing that could be really funny once, but once the humor wears off (and it may rather quickly depending on the group) I feel this creates a mess that will be more trouble than it could possibly be worth.
[obviously this isn't the main point of the spell, etc, but it's on the sheet, so it exist to tempt people to do this...]