Half stops... my head says yes, but my heart says no.
This isn't really the practical answer you're looking for, I'll bet, but while I like the functionality of them -- they're safer, and sometimes it's actually kind of nice to use a knife that's half open -- I don't really like the "feel" of a half-stopped knife. It feels like a scratch looks.
Honestly, though, I could take it or leave it. Pluses and minuses balance out pretty well.