If you need to access the internet and download a lot of data (like Apple updates or post lots of pictures for example) the data plan rates for smartphones are the highest ones around. Much less expensive are the data plans that feature a USB or Expresscard modem. Even here the reseller for Verizon data, Millenicom.com, provides 20GB per month at $20 less than the Verizon plan that has a 10GB monthly limit.
Verizon as of today has 4G coverage in less than 5% of the USA and in reality it provides 4G only in major metro areas, so 0% coverage in Montana or WYoming. 4G in Utah is only available in the Salt Lake and Ogden metro area, in Colorado only in the Denver metro area, in Georgia only in Atlanta, in Northern California only in the major cities. Once you drive 10 miles outside the cities the coverage is 3G only and that is across the entire USA.
We have a 3G only modem as 3G service is all we can get at our house and all we can get on the road 99.9% of the time. The 3G only modem provides a much more stable connection. It is important to go into the diagnostic mode of the modem and set it so it does not use 1xRTT and only CDMA. The CDMA is 10x as fast but the modem will pick whichever transmitter is providing the strongest signal.
If the nearest tower is transmitting 1xRTT at -75db and the CDMA signal is -80db the USB modem in its default mode will choose to link to the 1xRTT signal and the result is a very slow, as in dial-up speeds, connection.
With the added performance of a USB modem in a wireless router it is easy for multiple computers and people to share a single connection even when traveling. Much cheaper than paying for access in the parks.
One alternative we have found is that the public libraries have free WiFi and so when we have needed to upload or download a lot of data or found ourselves in a cellular black hole (not uncommon in California) we stop at a library for a couple of hours.