I am one of the Millenicom refugees who went with Verizon's offer when Millenicom had to cut us loose. Verizon gave me 20 gigs of 4G data for $100 to use on my Jetpack. I also was using Straight Talk for phone service (IPhone 5) at $45/month which ran on the Verizon system.
Yesterday I switched to the Verizon unlimited plan for my phone. $80 for one line. That gets me 10 gigs of 4G data and then 'unlimited' data at 3G. I will use the phone for tethering. The most interesting thing to me is that I can add a mobile hotspot (Jetpack) for $20/month. The Jetpack would also get 10 gigs of 4G before it drops to a slower speed.
I will obviously be cancelling my Verizon 20 gig data plan.
So I will see how it goes. If I use up the 10 gigs of 4G on my phone and I find that using my computer at 3G speeds is too cumbersome, I will add the jetpack. Then I will have 20 gigs of 4G for $100/month. And I will still be saving money.