Is there any reason to upgrade to Maemo 5 20.2010? Frankly, I am happy with how everything works now and see no point in upgrading. It's just this update tool that reminds me once in a while about this upgrade possibility.
So, any suggestions? What does M5 20.2011 actually bring? Only qt4 libraries?

Thanks

Welcome to the forums......
So... ur still on the oldskool firware?

Huh, and what do you expect from someone using an oldskool phone...

http://wiki.maemo.org/Maemo_5/PR1.3

It gets you a bunch of bug fixes, pretty much. If you're happy to be on PR1.whatever, sure, sit on it. But I don't see why not. It's like opening up Firefox, and having it say it has updates, but saying "frak it, I don't really need updates", and not bothering. For months.

The really good question is, why not? If you can do it by app manager with the SSU, instead of by reflashing, I don't see a good reason not to update it. if you can't without reflashing, then yes, that can be annoying, and I say your device will be mostly fine without it, so if that's too much effort, you might as well not bother.

But keep in mind that the longer you wait the more likely something is to break because the new packages expect PR1.3 versions of things.

Depends on what version you're using now..

At PR1.2 there was a huge optification done, that had a negative performance impact, though it freed up more rootfs space.

Updating to the latest fitmware

As Mentalist Traceur already said, you can have troubles with some apps that requires you the latest firmware.

Currently, it is Maemo 5 10.2010.19-1 firmware version, and yes, app manager proposes an update, which doesn't assume reflashing.
Among the new features that appeared with PR 1.3 I cannot see anything that I really immediately need. As for the bug fixes, this is one of the two that bothered me
- Skype shows me as the second party in conversation.
The second - being the habit that the Conversations app developed to hang up twice a month.
So far, what is important to know:
1) Will my customisations disapper after the upgrade?
2) What will happen to my SMS-base?
3) Will there be any decrease in memory space after upgrade operation?
Have you moved to PR 1.3, by the way?

As for Firefox, I have disabled any popups that inform about new versions/missing plugins.
Perhaps, this illustrates my attitude towards "new".

Before this upgrade what are the recommended steps?
If, say, I would like to have an opportunity to downgrade in case I don't like the new firmware? Is this possible? How do I make a full backup of the system then? (don't you mind such questions being asked in this thread?)