I noticed that unlocked phones show they support all the major bands. Whereas the locked phones only show their respective bands. For example: the SGS2 T-Mobile only shows their UMTS bands being 1700/2100, 2100 vs the Unbranded one which has 850/900/1900/2100 and then there's the Gnex that has 850, 900, 1700/2100, 1900, 2100. Does that mean that potentially the unlocked versions could have better 3G+ reception?
I have my M-Defy here and switching basebands to the 850/1700/2100 gave me great 3G reception in my house, whereas my branded Vibrant barely has any 3G reception and often switches to EDGE as I learned it only supports 1700/2100, 1900, 2100. This is also backed up by the fact that unlocked carrier phones are limited to only their GSM speeds since all GSM frequencies are supported on any phone but the UMTS bands are special to each carrier: the iPhone for example plays a huge role here and ever since TMO acquired some AT&T Spectrum: my iphone 3G does get 3G coverage and AT&T's 3G does cover the 850 spectrum.