R' Chaim Kanievsky shlita davens Ashkenaz and wears Ashkenazi tefilin. His grandfather z'l was a Chernobyler chasid. It's not clear to me how the Steipler Gaon ztz'l conducted himself with regards to tefilin and nusach. The sefer Orchos Rabenu might shed some light (and if anybody knows where to buy this sefer, please share!). It is also known that the Steipler did not eat gebrokts, a chasidic minhag. When and why was the switch made from Chasidic to non-Chasidic customs, and what was the basis for doing so according to the one who made the change?