If I remember correctly, ME stood for "Many Errors"
Oddly enough, a lot of people I know who haven't upgraded to XP yet have been experiencing awful problems running their PC's smoothly. I've been fixing a lot more of my friends setups recently - for free! (although one of them did cook a wicked dinner a few Sundays ago)
Anyway, considering they're free, those express versions are worth playing with. But compared to C++.Net 2002/2003, there are a quite a lot of features excluded such as making DLL's and the optimised compiler amongst other things.
Another thing, when you use an Express product - be clear about the licensing of selling software built with an Express product. Maybe you should check that out.
I'd imagine C++ 2003.Net is the most fully featured and stable one out the lot and also has no license restrictions.
I thought I bought an unregistered C++.Net 2003 via eBay, really cheap - but it was the 2002 version (damn some of those eBay sellers and their lies!). I did ask the seller and was told it was 2003. Seller left eBay after that.
I could most probably get an upgrade to 2003 from MS. Never mind though, at least it works and was genuine 2002.
Not like the full Visual Studio.Net 2002 I bought before that, really cheap. It was a bloody beta version and it time-bombed on me (double-damn some of those eBay sellers and their lies!).