I was recently in this position, chose to leave my program, and did my best to leave on good terms. Ultimately the relationship with my advisor soured.
I believe the most important question to ask is whether you will be happy for the next 3 or more years continuing to work under your advisor. You should be fine without a letter of rec. from your advisor.
I believe the most important question to ask is whether you will be happy for the next 3 or more years continuing to work under your advisor. You should be fine without a letter of rec. from your advisor.