Zed Shaw, the author of the latter, actually has a big rant on why he doesn't recommend Dive Into Python.
http://oppugn.us/posts/1272050135.html
Here's are similar comparisons between my book and Mark's as documented by Eric Wilson both on his blog as well as in an Amazon review... see http://amazon.com/review/RKG44D8GQYLNL and http://wilsonericn.wordpress.com/2011/09/26 for details. So yes, some people don't like it, but to others, it's just what they needed.
Zed Shaw, the author of the latter, actually has a big rant on why he doesn't recommend Dive Into Python.
http://oppugn.us/posts/1272050135.html