I can't speak for any of the others, but I simply ordered my Linutop from their shop and paid with PayPal. It took quite a while to arrive, but that was because I pre-ordered. These days it takes less than a forthnight.

About the experience: I haven't had any (yet), beyond turning it on and see if it boots (which it does; boot is very slow, but the Linutop is meant to be left on). The Linutop was meant to serve as a secondary pc, attached to a flatscreen tv with VGA input, in our new home in Thailand. Due to all sorts of legalities, we're not in our new home (yet), so the Linutop sits on a shelf, collecting dust. I did buy a wireless keyboard-with-trackball that works fine with the Linutop.

The company does follow up on its product and has released several software updates already (see here for more info). I especially like the fact that everything, including the OS, runs off a USB stick; the plan is to give every member of the houshold their own stick, so there's no messing with other people's files (and pr0n!)