Here's a quick-n-dirty test:
sleep 60 &
nice -n 15 sudo sleep 60 &
sudo nice -n 15 sleep 60 &
ps -al | grep [s]leep | awk '{print $1,$2,$6}'
This returns the UID, PID and nice value of each sleep command. The first will be have your UID and a nice value of 0, the other two will be...