Our requirements for this were more than just a donate button. We wanted our members to be able to specify the amount they wished to donate (but suggest a suitable amount at the same time); choose to make a one-time donation or regular monthly donations; and donate in a variety of currencies.
We also wanted IPN integration that would pick up subscriptions previously set up and donations made directly to our email account @ paypal; keep track of and display recent and all time donors; and show a graphical display of amounts raised vs. goals.
The Free PayPal Donations extension met all of our requirements.
Setup, which at first looked like it would be easy, turned out to be a little tricky and we found the documentation for the extension to be a bit lacking. Still, after reviewing what documentation that did exist in the program and the author's web site, we were able to get it up and running; it just took a little longer and was more difficult than it should have been, in my opinion.
Once set up, the program has functioned well. This is our first month using it, so we do not know how it will be once we go into a new month and a new goal.
Overall, I really do like the program but the thing that kept me from giving it an Excellent rating is the lack of documentation. There are still many things shown in the setup that I do not understand or which appear to be non-functional. Perhaps this will all be worked out in future releases.
Support has been decent, given via a forum on the product web site.
Response time for questions asked appear to be prompt, but it is evident that this is a sideline project for the author and not his primary focus. For the price (Free > donation), this is to be expected and I did not fault him for this.
So, to summarize, this is a very capable program which will do what it says it will and works well once set up. Documentation is a bit lean for my taste and support, while prompt, does not appear to be a priority.
Despite that, I do not know another program of this type that has all the functionality, so that makes it well worth the learning curve required to get it set up and running.
Rating: GOOD (But could be EXCELLENT with a little more docs and support)