I changed to customs from stock because the stock 2.1 auto-reboots all the time.
I am not sure if it is problem with link2sd since it is not happening with firt 20 apps anyway. You can hardly install more than 20 apps without link2sd.
I am now using cm9 and the offical app2sd works ok. link2sd doesnt work for cm9.
link2sd supports to auto install to SD. several important difference between 2.1 and 2.3 :