I just use wget on a nightly basis. FWIW, here are the parameters I use:
-N - turn on timestamping
-r - recursive
-k - convert links
-nv - Turn off verbose logging
-o - output log
-i - input file of sites to crawl
-m - mirror
-w1 - wait 1 second between requests
--random-wait - use random wait times between requests
-np - no parent, never ascend to parent directory
-p - download all page prerequisites (stylesheets, scripts, etc.)
-X - directories to exclude
-R - file names to reject
-H - span hosts (limited by -D)
-D - domains to crawl (limited to these domains)
The biggest problem is most pages Blogger returns do not have a Last-modified HTTP header in the response, so it re-downloads unchanged files and logs the following message:
"Last-modified header missing -- time-stamps turned off."
If I could figure out how to squelch that behavior I'd be happy, because that's what makes it slow and also my local backup has to deal with those files every night because it thinks they've changed (when they haven't).