In recent years: Samsung has done well to resolve the one problem I actually had with their firmware updates: the lack of security patches.
Generally, I found upgrades to knew versions of Android were nearly a year behind their phones. Perhaps a small price to pay given they were largely stable releases and the tablet builds cut most of the bloat from their phones while keeping the useful features.
Android has also evolved into such a state that I don’t really care about getting the latest version of the OS anymore. By the time Google does something user facing that worth while: it’s almost time for a new device. Kind of like a certain other operating system: the previous version or two still runs most of the apps.
The part that’s bothered me is the security updates. Most of my tablets didn’t get squat for that, as security was bundled with the OS upgrades and the occasional patch.
Meanwhile the Tab S2 and Tab S3 have been a very different experience versus the other Samsung Tablets I’ve owned over the years. Pretty much every quarter the security patches rolls out. Seeing security patches every 3-4 months is a lot better than every 8-16 months or so. On the flip side my Motorola on Google Fi gets monthly patching.