Looks like you yanks get a better product range than us Brits.
To be honest though, if you look at the various models there are not too identically specced models with different core/memory speeds. Take the 8500LEs:
64MB : 230/230
64MB TV : 250/250
128MB TV : 250/250
I do conceed, there are certainly different core/memory speeds, but can you buy a ATi Radeon 8500LE 64MB TV *RETAIL* that is clocked differently to the one above?
It looks more like there are a large range of variants of cards rather than identical cards specced differently.
Either way, when it comes down to purchasing products (especially ATI) know what your buying.
McEwin.