Woof I certainly would not argue with "wood carvers.org" and not being familiar with "basswood" I googled it and indeed it is a favorite among begining carvers.
It is a very bland looking wood,not very appealing to the eye, and quite boring from what I read it seems to be recommended to be painted for a finish.
Though still similar in usablity to white pine, I think the pine might still be a good choice esp when it comes to apperrance....
Here's a link that has lots of woods on them with description, and usablity and how recommende to be used, also a picture of the wood that can be enlarged.http://www.thewoodbox.com/data/wood/basswoodinfo.htm
P.S. even if you don't choose the walnut......its still worth a look for its beauty.