humor me (Score 1)

Ok, so I know there will probably be keyboards a'flyin' with this question, but humor me (please). I am strongly debating between purchasing the 600 or the 650. I've read all the reviews/criticisms for both units but I guess my ultimate question is - since I have NOT been a treo user before (only a palm vii once upon a time ago) - will the memory, lag and whatever issues on the 650 be all the noticable or a major concern for a "lay" user. My primary function for the unit will be for calls, about 200-300 contacts, email, messenging and some browser stuff. Your thoughts?