I've been using Ubuntu 14.04 LTS for about a year and a half now and I've loved it. I hadn't yet done the upgrade to 16.04 because I didn't have the time. I made some time the other day and opened the terminal and ran `sudo apt-get do-release-upgrade`. Quite frankly, I'm extremely disappointed. After taking 5 and a half hours to upgrade, my computer took nearly 5 minutes to reboot. I thought it was just a one-time thing (setting things up after the upgrade, similar to the Win10 upgrade). But it takes that long every time. Below are some before/after comparisons (14.04 vs 16.04).

* Boot time: Before - approx. 1 minute; After - approx. 5 minutes
* Login time: Before - approx. 15 seconds; After - approx. 2 minutes
* Shutdown time: Before - approx. 5 minutes; After - approx 7 minutes
* Memory usage at idle: Before - approx. 60%; After - approx. 80%
* CPU usage at idle: Before - approx. 20%; After - approx. 75%
* CPU temp at idle: Before - approx. 40C; After - approx. 55C

I have no idea why its so slow at everything now but I think it may have something to do with some packages not being installed correctly, or perhaps some old ones hanging around sucking up processing power, however, I've run `sudo apt update`, `sudo apt upgrade`, and `sudo apt auto-remove` multiple times each. Is there a way to clean up my system and make it run better?