There is a "sometimes" kinda problem with the mirror servers where updates come from. Both the Software Center and the terminal can time-out partway through a large set of upgrades.
Generally speaking, until the Software Center gets replaced as planned, it's better to update from the command line. Try using this command:
`sudo eopkg up`
That will update the repository and go on to upgrade all the changed packages. The great thing about doing this from the terminal is that it's super easy to restart. Just issue a Ctrl+C, just as you would in Windows, to break out of the stalled update, and press the up-arrow key to repeat the above command.
The update will restart, and it's smart enough to quickly advance to where it stopped, and pick up again where it left off. By the way, updates are usually released every Friday morning. If you want to see the rest of the commands that eopkg will respond to, try sudo eopkg -help.
Enjoy Solus! I went through the same process you did when I left Windows. I tried 36 other distros before I fell in love with Solus!
