I think you are over-analyzing, but at the same time, without system specs, there isn't really any way we can tell you how we feel, is there?
Depending on those systems specs, it may run Windows 7 very well. One thing Windows 7 does well, and much better than Vista, is scale down to lesser systems. I'm sure many of us could post some "older" systems that we've been able to get Windows 7 running on just fine, but without knowing the specs of your "older" system, that would all be pointless. I'm not sure what you expect or hope to get out of a thread like this without posting specs.