I am a huge JetBlue fan overall (Mosaic for several years) but would hesitate to bet on them for a weekly commute. Their achilles heel, IMHO, is operational reliability. As someone else noted, afternoon flights are often late, and when there are weather or mechanical issues, they generally handle them much worse than all the legacy airlines (e.g. cancelling the entire schedule more often, not being able to rebook you on other flights for days, having to fight to rebook on other airlines, and communicating very poorly about the nature of delays). For a single round trip I'd take my chances, but if you are flying every week you will almost certainly run into some or all of these issues on a regular basis.