I have a H2 and am liking it. It does very well under a lot of different circumstances. I made the coolest recording of a woman very quietly saying a prayer in an old church in Syria, recorded some old-communists choir on the Red Square and have used it both for recording demos (for private use) and singing lessons for further studying.
It handles itself very well in a variety of situations, but if you plan to make more advanced ""layered" recordings, that is several tracks on one file, the H2 cannot do that. In that case I would recommend going for the "big brother" of H2. (can't remember the name sorry, but my friend uses one with great succes - as a matter of fact we used it tonight and it was, as always splendid sound)
They are both good. It depends on what you are after.
Hope it helps.
Lucas
*EDIT* oh... might be that the H4 is the aforementioned "big brother".. (duh)