I bought a US-20 and US-10 about 3 months ago - is this a replacement? No matter, I love them. Used them for a weekend in Bristol, about 150 miles of mainly motorway riding. The bags were used in the US-30 configuration with the 10 on top of the 20 and were absolutely rock solid at speeds up to 110mph or so.
They look great, are completely waterproof and hold a good amount of kit (I had casual clothes with shoes, going out on the razz clothes with shoes, climbing kit and wash kit, plus a medium-sized camera).
I'm so impressed I plan on getting one of the rucksacks, but it seems my short back (never realised that until last weekend) means I have to have the R25 as the R35 won't fit (hip belt up under ribs, back of back catches on helmet). The guy showing me them said the R35 is usually a problem for people under 6' tall...
They're very helpful, and I'm certain they'd ship to the US. Get them; they're worth it!