I do not know about other products - but I have been using Neat Video for more than a year now - and it is simply amazing what it can do to your source: i.e. a noisy low light restaurant recording with a 640x480 pocket camera can be cooked to a quite useable clip.
Please note, however, that Neat Video is really hard on your CPU power. Previewing on my double Xeon Quad Mac Pro falls from 25 Fps++ to below 8 Fps - but it is no problem - just apply Neat video at last in the editing process - or make an intermediate file.
Well I purchased the Home version of Neat Video for $49.95 and all I can say is WOW!!!!!! This works great on version 9a....saved alot of video that I thought was ruined. As others have said it is pretty taxing on the cpu....use it last in editing or just by itself. Great plugin!!!!