I like it, but only pronounced the Russian / Ukrainian way (ah-nah-STAH-see-ah). I realize this is pretentious in English and so really wouldn’t recommend it as a name here. The English pronunciation seems slurred and cutesy to me, so I really dislike it.
Nicknames that could work (with either pronunciation):
AnaStasyaStacie
*previously posted as sunmitseeker*--hike more / worry less--