I'd appreciate a couple of pointers about this issue; and I've a comment about the user-interface for VAT and product creation. I really wish I'd known about this before I plunged into investing significant money and time in developing a Drupal 6 site using Ubercart! Now I'm wondering if Ubercart is the right choice for us.

1. is this discussion confined to Ubercart 1 or does some apply to Ubercart 2? We've installed 2.
2. I've installed Ubercart 2 VAT support module; how well does this work? I've not met any huge hitches, BUT:
3. We're primarily a publisher and many of our books are sold in hard-copy AND in electronic form. VAT applies to electronic publications only The interface for defining attributes for products is great because it allows just one product page with paper and electronic variations (e.g. paperback, hardback, read-only, searchable, epub, pdf, mobi etc. etc.). As far as I can see, this discussion of VAT in Ubercart core assumes that items with different VAT rates are necessarily different products. But they aren't, in our case! Same product, minor variant, but price adjustments for variants would need to allow for the VAT rate to vary.
4. so, is it a mammoth and not-yet-started task to address that, and is it an issue that would be widely cared about?
5. one final note: the rules for VAT in the UK changed recently. As far as I know, we now DO need to charge VAT on qualifying items exported to the US, and on associated postage. At least, that's what the VAT office told us...