I went with the Managed Fusion Rewriter tool both for its promised flexibility and the fact that it used the Apache mod_rewrite syntax.
I like it, but I ran into a few quirks I thought I'd pass along.
First, if you're using RewriteCond and trying to grab query string parameter values, %1 will hold the name/value pair. %2 will hold the value you're probably looking for. If you have multiple values you're catching you would just continue to increment -- %3, %4, etc. Here's an example that works as I expected it:
RewriteCond %{QUERY_STRING} ^lessonid=([0-9]+)$
RewriteRule ^/Explore/KeyQuestions.aspx$ /Analyze/Display/%2 [R=301,NC,L]
Second, in mod_rewrite you can apparently stack multiple RewriteCond one on top of another. I was not able to get it to work with this tool.