I used to drive everywhere, but anymore, I can't afford to lose the hours on the road. I can work on the plane. As far as hassle, getting Global Entry was the best thing I ever did. Why people don't sign up for even bottom level Pre Screen I'll never understand.
we've done both. through agents and booking yourself. i prefer booking myself. (even though the agents get better deals on business... i once did a GSP-LGA-JFK- Nanjing-Shanghai-Quindao-Shanghai-Toronto-CLT-GSP and they booked it for $2600 business...)