I prefer 'still doll' for a few reasons:
1) The composition is MUCH better IMO...'Kuroi Torikago' kind of sounds like it's all over the place in some parts.
2) The cello parts are phenominal in 'still doll'. They're good in 'Kuroi Torikago' but not as impressive.
3) I thought 'still doll' was too short but after I heard 'Kuroi Torikago' I was like O.O....
...sooo yeah I apologize for the redundancy. It's not that I dislike 'Kuroi Torikago', it's just that it's not as memorable to me
....it lacks the haunting beauty that 'still doll' seems to has.