I tried SQL Servers compressed backups over the weekend.
Without backup 144 GB in 1 hr 45 minutes
With Compression 21 GB in 4 hours
So compression is very good for backup size but not so good for duration. If you have more data you need to allow for more time. It also uses more resource so if the server has to be online 24 / 7 it may not work for you. For my situation, size is more important than concurrency or duration so I am sticking with the compression.