My way to update/migrate from Joomla 2.5.28 to Joomla 3.3.6

I made a backup, downloaded it and tried to extract this in a dry run (for knowing, it's a good backup)
I choosed in global configuration>Server>Error Reporting: to Maximum and saved.
In extension manager I go to "manage".
I deleted some extensions I never or rarely used (and which I don't need).
It's better to make an official joomla 2.5 template to the default template.
I disabled all extensions (components, modules and plugins) where Author is not Joomla! Project
I had some extensions which have a unique version for J2.5 and J3. This one I let enabled. When I was unsure, I disabled.
I went then in Components to Joomla actualisation and choose options. I choosed "Short Time" and save it.
After refreshing I got the information of an update to Joomla 3.3.6.
I clicked that. The update is done.
After refreshing, I went to templates and choosed isis as default for backend and protostar as default for frontend. (But if I remember right, this was automaticly done)
A look in the frontend was ok.
In backend I updated all extensions which have a different version for J2.5 and J3. After updating they should be enabled or I had to enable it manually.
Like that I came to my actual version of Joomla 3.3.6.

I made this with two livesites (one with php 5.4, the other with 5.3.29)