I prefer UK's Sky coverage. They seem to be more in-tune with what's going on behind-the-scene, and don't worry too much about the gossips and rumors.
I'm rather content with the NBC's coverage because they _try_ not to disturb the race with commercials too much(and keep showing the races with Picture-in-Picture), which is in direct comparison with Speed's commercial every 10 minutes nonsense.
I don't know how I feel about the commentary, though. They basically rounded up the guys from Speed, including Will Buxton. They sounds like they're rehashing the old news over and over, though(and explaining the tire regulation over and over), and don't really talk about the new additions on the car. It's all to elementary, and there is more to F1 than what they're (able to?) deliver.
Oh the side note, watching F1 LIVE with the Timing App on the phone makes the whole experience more enjoyable. Live tire status(laps used), everyone's track position, pit-in/out timing, time gained/lost on sectors, time difference per lap, etc, is far more usable than waiting for the 'experts' to chime in and have them _guess_ what's actually going on.
It's a one (albeit major) step before the FanVision/Kangaroo TV(not available for 2013+).