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No, it's not a stupid question.
Anyone would expect that a 2.2 version is somehow superior to a 2.0.x version - but XOOPS is different.
Xoops 2.2 probably has a lot of fantastic features in it's core, unfortunately, a simple XOOPS user can not use them, because there are no modules shipped with XOOPS to take advantage of them.
You now have to look thru the Module Repository here on xoops.org and then thru countless websites of those people inventing those Modules to see if a module works with XOOPS 2.2 or not.
There were some "promises" (I should better say "quotes"), that XOOPS will be packed together with some pre-selected modules, unfortunately this hasn't happened yet. As long as it has not happened, I would suggest to use 2.0.x if you don't want to try out everything yourself.