We are implementing Django applications with Apache 2.2 + mod_wsgi. Should we enable mod_deflate in Apache or use Django's GZipMiddleware? Which option works better?

You need to most likely test to understand without a doubt, but when I would guess, mod_deflate would get better because of demands that totally bypass Django completely (like zipped up static assets that needs to be used individually i.e. media).

For stuff that happen to be produced by Django reactions, it's most likely a toss-up -- either in situation it might be native code doing the zipping.

It is dependent. Should you enable it in Apache, then it will likewise be utilized for static content (e.g. CSS, Javascript, images) however, many static content (like Digital, Presen, SWF) is fairly well compressed anyway.

I'd certainly opt for mod_deflate, around the assumption you have static css and js files which apache is serving directly and may also be compressed.