As you say, it really does not matter providing the device never breaks. If it does break, then usually there is some procedure for returns. However, customer support is one area where there can be large differences between companies. For a vendors perspective, see Robert B's blog post:
Support for EZ Reader devices outside North America.. I have not heard anything but good reports of Astak's service, but Robert B is simplifying a bit. It is easy to anticipate the shipping cost and extra shipping time. The less expected issues are language barriers, and different vendors procedures for tracking returns and what happens to them. I have seen reports of bad experiences with Bookeen and iRex, for example, which to some extent were caused by a lack of communication from the company. In fact, plenty of people in the US have sent their iLiad's (for example) to iRex for repair and gotten them back.
I bought an iLiad because it was a unique product and so I risked the odds of it breaking and having to ship it back from the US to Europe for repair (I did buy from iRex's dealer in the US). However, I bought an EZ Reader, rather than a BeBook, because of Astak's US site for returns. As it turns out, I have had no problems with either my iLiad or my EZ Reader.
With a new entrant into the ebook device game it is hard to know how good their support will be. The txtr does look like an interesting device from a dynamic company. To me, the unknown release date would be more of an issue than buying from Europe (assuming txtr sells to the US from its web site).