Depends on the coverage. The signal strength is independant on how good the coverage is.
Say you have 100% signal strength on a network with excellent 4G coverage but bullstuff Edge coverage.
Any cellular phone using Edge will take ages to load if at all.
I'm posting right now with 1 dot of signal strength and can load YouTube via 3G.
When I'm on the outskirts of the city with 100% signal strength, 3G has a very stuff coverage and even loading the BLF takes ages while my sister on LTE can load Snapcrap quickly.