Is donationware a good monetization model for developers?

I've been developing for Android for about 2 years (and ~1 year for iOS), releasing freeware and open source applications (mostly because my AdSense account was disabled in 2010), but recently I had an idea for a great app that I wanted to get some money, since it would take some effort to develop and also I would like to test this "commercial" model to know if this could make me invest more time improving and making my apps better.

Since my AdSense account was disabled and then I'll not be about to sell it on the Google Play Store, I thought about making it a donationware so I would distribute it for free (and probably open source too) and users that really liked the app and wanted to give me a thanks and a incentive to continue developing it could donate any amount of money.

So, what's your experience with donationware? Is it worth compared to paid apps?