Alternating scanlines do look really good in 480i. 🙂
I used to play Rayman without them on the old TV, but I think the scanlines look really nice on the OLED set, so I like using them now. They really seem mandatory in interlaced modes. Also yeah, they look fairly uniform to me, even in 2x.
EDIT: Just out of curiosity, what strength do you use your scanlines on?