I think you're probably more patient than I am Mark - I find rFactorcentral really hit and miss.
I often find a mod that takes my fancy only to find out the download files are too fragmented, there are data transfer limits on the servers they've linked to or the files aren't there at all. Clearly you're paying to belong to an organised community though. Free copy of GTR2 look, flog that and you've got three months free!
I do know what you mean oily, but it's never been that much hassle to get a mod sorted. I'm not entirely sure how the one click download thing works, but if it's download and install I'd definitely stay clear myself. I might be anal but I never trust installers tbh, I always install to dummy folders first just to see what I'm getting, even if I then let it run to my game location afterwards. Of course I could do the same for the one click I suppose.