I use a MacBook Air paired with an LTE iPad. The combo gives me great speed and roughly whole workday battery life. If the MacBook dies after 5 or so hours, the iPad will still be at 90% charge and is fine for ssh/vim. This rarely happens though...

As a fulltime contractor with no office and lots of fun places to sit, I love it. But yes, it's $2k + $50/month for the LTE.