I was about to say that there have been a lot of posts about issues following updates on Samsung devices. However, given their market share, a larger number may still not be a large percentage, so let's just say "quite a few". The problem isn't completely confined to Samsung and, again, the size of the user-base may be exaggerating things.
However... A number of people have reported issues with freezing, unresponsiveness and and high battery consumption following a firmware update. In most cases a factory reset solves the issue, clearing out any bits of the old code that are hanging about in the system cache. It's a quick(ish) fix, but still a bit of a pain, as you have to backup and restore content and set the whole shebang up again from scratch. In a few cases, the problems persist and your pride and joy has to go to phone hospital for a reflash of the software.
Whenever I've done updates on Samsung devices, it's been on older ones with limited memory, so I've done the reset first to give the poor thing enough space and resorces to go about its task. However, I've been wondering whether, in a lot of cases, a simple restart wouldn't be enough? After all, if you haven't done one for a while, apps will have built up caches and have running processes hanging about, all eating into your precious RAM. On my aging Tab 2, I frequently have to clear its meagre 1gb of RAM after only a day of use just to get it to be able to overtake a snail in the slow lane.
So, this is a suggestion (perhaps even a bit of a plea). If you're updating a Samsung device, do a restart before setting about it. Post here with the result and lets see if it reduces the number of resets required. It's not as if it'll take more than a couple of minutes extra and may save you a couple of hours. When I updated an HTC One M8 from KitKat to Lollipop, the process went smoothly and was done shortly after starting the device.
The other thing to consider, of course, is available storage. The update process should check that, but there'll be working files that are produced and, if you have a lot of apps, music and photos, it could all get a bit marginal. Maybe move some things to an sd card or even a pc, even if only temporarily.
I'd also be interested to hear from people who've updated via Kies. In theory, this should do most of the work on the pc and reduce the workload on the phone. Does this route produce problems as well, or is it more reliable?
