As you know, I buy a fair bit from Germany. I've learned that when I have to purchase from marketplace sellers or eBay sellers from Germany, 80% of them choose the poorest method of postage you can imagine.
The last book I received (which took 87 days to arrive - airmail) had been so poorly packaged (well, it was stuck into a bubble-wrap parcel envelope where the tacks fastening the envelope had come open in transit, thus exposing the top of the book) that I was frankly amazed the book arrived completely undamaged.
It certainly took much longer than I'd hoped to arrive. But another book purchased on the same day from another seller ALSO took around the same time to arrive (89 days).
Buying from the German Amazon site is fine - the postage is timely.
Buying from French sellers is usually not bad at all. I can most frequently count on receiving my orders in 2 weeks.
Buying from Italian sellers - slow, and in one case (remember the plastic-wrapped Italian games?) badly damaged. Yet Italians are lovely people in general...
Buying from UK sellers - outstanding. I think my best buying experiences have been from the UK. Fast postage, absolutely fantastic packaging, terrific people.
American sellers vary. Most of my sellers have been good, but the handful of items that were never sent by the sellers were American. It does of course usually take at least 2 weeks (and sometimes 3 or 4) to receive items from the US unless they're sent by courier. In general, I love the American sellers.
And of course the excellent Australian sellers are something special... The best DVD wrapping/packaging I've ever seen comes from Smee, for instance - and you absolutely cannot beat Australians for whimsical niceness and a fair deal (apart from the occasional naughty larrikin).