Difficult to know what sort of performance you will get out of it, but my expectations would not be very high. It gives a video resolution of 640 x 480 pixels, so not really worth having a camera with more than 480 lines. Bit rate is relatively low, but MPEG4 gives better compression than MPEG2.
Again, it depends on what you are going to do with the output - playback in a window on a pc should be ok, but if you wanted to make a DVD you would end up needing to convert MPEG4 to MPEG2, which is likely to give you lots of artefacts.
I'd have a surf and see what people are using it for, and how they rate it. Better still if anyone has posted video from one you will be able to see exactly what you will get.
You didn't say what you disliked about the Action 2000 camera?