I'm running 2 sites, one on 2.2.4 with no problems and one on 2.0.13.2 also with no problems.
Yes the version numbering is confusing at first! The open project of XOOPS is/has and will be a work in progress. I have learned not to upgrade too fast in a production site. But I have and encourage you to test out new versions localy, using xampp or some other server platform. (I like the flexibility of xampp)
As the XOOPS developers span the globe it isn't always easy to get through to everyone as context is interperted differently. Once you grasp that concept, it is much easier to understand (does that make sense?).
In addition, I use search here alot, there is a lot of information here and most times the questions have been answered previously. I think because this is open source you are encouraged if not expected to do your own research before you cry too loudly for help. A lesson I learned long ago.
Just a note to thank all those who work on XOOPS development, upgrades and modules......... cheers