Well I bit the bullet and did the upgrade between LTS versions of Ubuntu over the weekend.
After backing up everything I ran the 8.10 -> 9.04 -> 9.10 -> 10.04 upgrade sequence. I'm not sure why I didn't just reinstall from scratch - it would have been a lot faster although I would have had to spend the time adding the extra programs I regularly use and I hadn't backed up all my VMWare Server virtual systems that I use for testing so would have had to go through a few hours of fun with that.
What was good?
Everything pretty much just worked - albeit somewhat slowly.
What wasn't good?
Took a long time (downloads ran at under 100k/sec a lot of the time - ain't broadband fun. Luckily I didn't have to sit in front of it and wait.
Some 'features' of newer versions of software are on by default and that is a pain. I don't want my password safe to lock after 2 minutes. I use it frequently at times and my pass phrase is long enough that it is a pain to type in too often (i know - its a trade off). And why do I now have to type in a password I never did before when using Thunderbird which has saved my Gmail login password?
And why does Thunderbird now start with a new set of defaults that I have to change back to how I use it?
It installed a set of games that I didn't want. Surely even a dist-upgrade should take some notice of what is already installed and if I have removed all games please don't gratuitously add them in for me - likewise a bunch of new apps I haven't even heard off. What are Akonaditray and Gwibber anyway and why do I care? Give me choice if necessary.