Seriously? RIM doesn't even say the 99xx is a 4G device. My friend's 9900 H+ is slower than my 9930 3G. H+ can't hold a candle to LTE which is why AT&T and Sprint are making the switch. I feel bad for T-Mobile users because as far as I know they aren't switching to LTE like everyone else.
Me and my fiance's 9930 are both made in Mexico and have not had any issue with them at all.