No chance, don't believe this
I use my phone extensively in the US and have had an account on Verizon and recently AT&T. Verizon is faster and on average around 15m/bit, AT&T usually about 10. Occasionally conditions are good, near a mast in an upgraded area with LTE-A I can get 50m/bit but mainly not. I've not tried sprint's new network with CA but I've heard it is fast.
In Europe I use a UK Vodafone contract throughout Europe and my usual speed is around 20m/bit and up to 60m/bit in big cities. EE data card gives me up to 120m/bit and I've had that in London.
There's no way the USA is faster. Friends who've been in the U.K. On 3 prepaid SIM cards said the 3G was faster than their LTE.