Don't beat me, but still on rails 4.2 and happy... Gives me everything I need for no/low JS backend SaaS stuff I do for my self and B2B companies, running on low end VPSs...
If you have time to answer - why would I upgrade?
If you have time to answer - why would I upgrade?
The main thing with older versions is vulnerabilities in associated gems, e.g. nokogiri which you can't upgrade without a major rails upgrade. However most apps don't do fancy XML parsing for example so most vulns are not applicable. So there is a bit of maintaining to ensure things are safe. Often you might add in a monkey patch to cover a bug.
Upgrading therefore makes it more secure and lowers maintenance time. However there's the cost of the non stop upgrades to factor in. Another factor might be faster Ruby support in newer versions.
(Generally when I make a rails app I use the latest release but I don't upgrade the rails version afterwards unless it's popular or the app is very old and stuff doesn't work on newer systems)