30mbps should be good enough if you are trying to use it on multi PH operation. If you want to install IP came for the security camera watching and VPN from outside, then you may use 7-10Mbps temporary for the access and another 2-5Mpbs for the video watching or playing with your drone flying over the mining farm.
You'll always do better with your own node.
EDIT: assuming you have the bandwidth for it.
Question on this...
What kind of sustained bandwidth does a normal mining operation consume? I have a 30MB up/down pipe and was wondering what I should allocate. I can build a DMZ for my local P2Pool server to run on, and set the limits on bandwidth. Would 2MB be enough? More?