I personally do not find the ex-VX F seats very comfortable for sitting in — the seat pan is really long (and I’m 6’ tall), so there’s basically no back support. So I generally would not pay $250 extra for it regardless of financial circumstances. But if you need extra legroom (I assume you don’t qualify for Premium seat upgrades) or, more importantly, width, then it’s probably worth it. The food and extra service are forgettable at best.