I bought Code 2e from the MS press store just this week.

I downloaded the epub, Calibre converted it to mobi when I said to deliver to my 2014 Kindle. Looked kinda crappy.

Downloaded the mobi direct, sent it to the Kindle. Looks much better.

The conversions are not always quality.

Hmm i only do fiction on readers (kindle or tablet). I guess technical books with diagrams and fancy formatting like sidebars etc would be a problem.