Well, in most cases, yes. But there is still some occasion where Force bi\trilinear filtering can be useful. Here is two screenshots. The first one is R 2595, Force bi\trilinear filtering, Anisotropic filter 4x. The second one is R 2629, Anisotropic filter 16x, Antialias (MSAA) 16xQ CSAA. The first one looks better for me. The game is SoulCalibur II.
Even better example. Resident Evil Remake. R 2595 with Force bi\trilinear filtering & Anisotropic filter 4x VS R 2630 with Anisotropic filter 16x & Antialias (MSAA) 16xQ CSAA. Just look at the floor reflections.
I've discovered a little bug here (R 2634, R 2639). For some reason Dolphin likes to uncheck Force bi\trilinear filtering feature. I can turn it on, but when I'm closing OpenGL configuration window and then opening it again, feature box is always unchecked.