Hi,
Well, any of these older cameras will always produce the same results as they did when new. And, it is good to fire them up fairly often to keep all those capacitors inside them working. Those components tend to fail when left unpowered for long periods of time.
The good part is we get to use them when we think about keeping them operating. In my case, I have a 760c and, at this time, it is the only DSLR I have. I had both a 720x and a 560, but let them go to others who still wanted to use those models for paying work. Come to think of it, that is why I let all the various DSLRs go over the years. But, I was getting the latest and greatest for years there, but jumped off that bandwagon after I became tired of always overspending.
One thing to consider when using older models. The processing software and computers. Eventually, the software will stop supporting older stuff, and then the older versions of the software will stop running on newer hardware and operating systems. So, we all need to give some thought to having enough older equipment to support ourselves when the time comes that we realize the latest stuff no longer processes our older image files.
I have been dealing with this for years now when it comes to older radio gear. Programmimg software that runs under DOS and on nothing faster than a 386 at 25 MHz, for example. In time, it will happen to digital image processing. In fact, it has for some models already.
Stan