There are two folders:
29 Birds of Legend & 29 Birds of Legend for DS3
I'm using DS4.7 ... so which one should I keep?
dump the DS3 ones-- DAZ significantly rewrote their Poser code importer in Version 4.0+ to conform with all Poser coding. Version 3 or earlier versions didn't allow Poser's Propagating Scaling of child items which Songbird ReMix uses heavily.
I've discontinued support of any version of DAZ Studio below v4.5
I'm currently supporting Poser 9+ (although any of my birds will work in Poser 6).