I use them,
I like there setup better than most.
Very good stats, and the person who payed with them have the username and password in their own Paypal account, so they don't have to ask you all the time...
PayPal even offers a rebill option..
They will help you set it up on your server as long as you are not on a NT or win2k machine..
Mine site with paypal is
www.gotgauge.com