Yes, I think Picasa was a bit better in that respect. But I've just noticed that you mark and tick many pictures at once, so you don't have to click on every tick in every image. Hope that helps.
But I managed to confirm a lawn as being an old friend. I've no idea how to unconfirm that photo. Any ideas?
Delete the face region. In People view, select the incorrectly confirmed "face" and either right-click and select "Remove Face Region", or simply back-space. In Loupe view, enable "Draw Face Regions", click the region to select/highlight it and click the "X" that appears top-right corner.
having the same issue, worked fine up to 2k faces, now the suggestions are very very bad - having about 50 different people the suggestions aren't useful at all anymore. Defeats the purpose if I have to enter every single face manually. Before the 2k faces I the guesses of the software were 90% accurate.