I guess it depends on the way you look at it and how you value the ability to capture your work. Foreversave does work with GarageBand (at least the older version did. It looks to have been recently updated). It does have versioning, but it also has ways to manage how many versions you keep and how many times it saves, so nothing is really lost and everything can be undone. If space is an issue then upgrading your HD is not really a big deal, and even simpler is to get an external HD (you should already have 2 anyways... the old saying 'if you don't have at least 3 copies then your data is in danger'). Professional artists who use improve as a means to create and explore new material save everything... and I mean EVERYTHING. Saw an interview with the people working with Peter Gabriel and they have truck loads of redundant HD's and every single thing gets recorded and documented. Now us mere mortals don't have his kind of gift or team behind us, but technology is not exactly excluding us any more from a workflow like this is it?
On a side note, when I reccomended Foreversave, it was based on an older free version that worked with GB and Logic. Its since been revamped. I am looking into it now because I want to use the new vrsion and its features. I will report back when I find out more. 🙂