i haven't actually seen any of the sequels. i think they say 2 is good, but after that a drop-off in quality. the same with any other series, i guess.
if netflix has them, i'm not opposed to watching all of them and letting you know.
on friday night i purchased KUNG-FU ZOMBIE from best buy, which has some good taoist magic/zombie stuff going. generally the movie was in the 'unwatchable' tier of late 70's HK, but i enjoyed it.
ENCOUNTERS OF THE SPOOKY KIND has some great moments with sammo hung and a hopper. it doesn't feature the vampire too heavily, and it could have been edited better, but i recommend it.