Depending on the time of day and region your 4G LTE speeds will differ. Where I am I consistently get 40down on LTE, as compared to my wifi which barely burps out 3down. However, I've seen my LTE dip to 15 or even 12 on some days. I imagine as more people get 4G phones, the more congested the network will become. Verizon's 3G network is atrocious... so maybe a couple years down the road that -may- happen to it's 4G network, however unlikely it may be.
I've intermittently used my 4G connection as my primary home internet due to its amazing speeds and reliability. Latency is also relatively low with Verizon. Definitely one of the best, if not the best, carrier in the US.