I tend to like tsundere only in romance, where they're without a doubt the FMC, so they... are allowed to be silly. In harem, it just seems stupid and forced them winning, at least to me. The only tsundere in a harem I actually rooted for was in Ai kora, and just because the other girls were sort of insipid.
Ichika is nearest to my favourite kind of character among the sisters, but it's frankly hard not to root for Miku, jeez.