I have a SB in the UK and I view it in the US.

My specified u/l in the UK is 2.8 Mbps; I measure the u/l to a UK speed test site at about 2.6 Mbps.

My specified d/l in the US is 3 Mbps;  I measure the d/l from a US speed test site at around 2.75 Mbps.

My actual streaming rate from UK to US is around 950kbps.

A friend of mine has a UK SB (with u/l speeds measured at around 2.6 Mbps) and is viewing in the US with specified d/l speeds of 6 Mbps (don't know what his measured d/l speeds are).

He has a streaming rate of around 1.2 Mbps, but his ping times (around 165 msecs.) are shorter than mine (around 210 millisecs.)

When I measure u/l speeds from my UK location to US speed test sites, the speeds are much lower than when measured to UK speed test sites.  They are even significantly lower than my actual streaming speeds.

Other factors which may impact your actual performance are whether your ISPs (at either end) have traffic shaping policies. 

Hope this helps.