I've purchased plenty of products from jr.com. Two camcorders, two batteries, one charger, two cleaning tapes, a smartphone, and a tripod.
Delivery charges: $35 American on average for UPS Worldship Express, $43 USD for the smartphone, which was a Nokia N900, the most expensive product I've ever purchased from them. The shipping charges include customs charges, but not GST and PST which is payable upon delivery for personal purchases, and payable upon receipt of the UPS bill for businesses.
All deliveries arrived double-boxed, undamaged, and in their original packaging.
Jr is in New York City, I'm in Montreal. Nearly every delivery arrived overnight, with only one delivery arriving a day later after shipping.
Only the tripod was back-ordered, and it did take a while for it to arrive. However, all the other retailers were also back-ordered or were asking too much. But as soon as jr received it, it was charged and shipped out the very same day.
The smartphone, while it was in stock, did take an extra day to be shipped out, more specifically on December 23, 2009. It arrived the next day on December 24.
The only product that turned out to be defective was one of the two camcorders. But because I had the camcorder for more than a month and it would take too long to have Canon repair it before my European vacation, I ordered a replacement camcorder from jr.com which is still working properly to this very day.
Jr's pricing and the current exchange rate does make it worthwhile to take a chance with purchasing medium to large ticket items from them (even the bad camcorder was priced considerably less in the States than here in Canada), but do make sure the manufacturer will honor the warranty for a product purchased in the USA and used in Canada. Some manufacturers can be openly hostile to cross-border purchases to the point of absurdity.
Overall, I'm extremely satisfied with jr.com and continue to use them both for cross-border purchases and for pricing comparisons.