Hi,
Ive had a NEO2.2 modded ps2 for almost a year now and even though i dont boot it that much these days it did used to get a right hammering and it still boots backups fine. Make sure you add the Cap and take your time doing the install.
What version ps2 have u got??
If i was going to put a new chip in ild go for a next gen chip ie Messiah the NEO 2.2 is a little out of date these days but you cant take its realibilty and quality away from the old boy.
Good Luck
Dal