BlueberryPy author here. Allow me to plug CherryPy and my micro-framework built on top of CherryPy called BlueberryPy.
Here's my answer on stackoverflow early last year when someone asked for a CherryPy vs Flask comparison. I believe all the points still stand and still represent CherryPy's strengths.
1. Simplicity. Controller object trees more or less equal to how you would define your URLs.
2. Flexibility. In case you don't like how the URLs are defined by default, you can use routes or methods to expose your URL handlers, which are just as easy.
3. Tools. CherryPy isn't religious about WSGI, though it's 100% compatible with the WSGI spec, the recommended approach is to use Tools. They are simple to make and use, and the way they are wired to the request is a lot more efficient than WSGI, which typically a request has to pass through whether or not that particular WSGI middleware is relevant. (Unless you use a framework where each URL handler is a WSGI application, but wiring up WSGI apps are still annoying). There are LOTS of them supplied by default that cover most of the use cases you can think of.
4. Plugins. For cross-cutting concerns, engine plugins are a much more granular, well-defined, and suitable way to deal with them as opposed to a WSGI app, which is typically the hammer people use to hammer in every screw these days.
5. Easy chunked responses. You just yield a string in the controller and that's it. Very useful for returning large documents in pieces.
6. Full-featured request and response objects. WebOb and CherryPy are about the only 2 frameworks that have comparably complete implementations of them, but I'd still choose CherryPy for the last reason:
7. Zero dependency on other packages. You won't bring in a dozen other libraries just to run a server. You just easy_install or pip install cherrypy and that's it.
Its WSGI server is also the canonical choice if you need a fast and stable pure Python WSGI server implementation. It's actually really really fast and stable:
http://nichol.as/benchmark-of-python-web-servers
Now, I've been using CherryPy for about 5 years now and am still absolutely in love with it. I love it so much that I've decided last month to open source the micro-framework I've built on top of CherryPy called BlueberryPy:
https://bitbucket.org/wyuenho/blueberrypy
It's basically a set of additional tools and plugins for CherryPy which give you an easier integration with SQLAlchemy, logging, Redis and Jinja2, webassets and various other goodies. It also comes with a project skeleton generator akin to many other frameworks out there but doesn't get in your way with the generated source files. All that BlueberryPy asks for is a configuration directory with a few correct YAML config files with a few keys pointing to a few classes in your package. Documentation is a little light but more will come soon enough as I find time to finish them up. Stay tuned :P