Be careful when flagging such comments. One or two are OK (I'd probably pick 'not constructive' because, well, it's not a constructive comment. Or it's 'obsolete' if it's already been accepted) but any more and you're just going to add loads of flags to the already massive flag queue.
Don't go hunting for these posts, only flag them when you find them organically, and only then if you really feel you must.
If you flag too many they'll just all get declined and that'll go against your flag score, so ask yourself if you really need to have these comments removed or not.