Not sure why somebody would recommend not to use goomanager. I've always used goomanager to install TWRP on my devices - hasn't caused any issues so far.
goomanager is nothing but a front end to a site that hosts files from developers. They provide an easy download option, and they check to find the file that is compatible to your phone. They also provide an easy way to reboot to recovery (instead of using the power/volume button combo).
If you don't want to use goomanager, you can always flash it (odin). Just make sure you download the version that is compatible with your phone.
20gb free cloud storage with this link