With my current setup (power/toughness/healing power) of armor and accessories I have about 14k hp and around 2800 armor. Sure, the HP pool is pretty small, but whatever damage I take I simply use one skill and it's back up. I don't really ever die in dungeons and I'm able to actually do some real healing.
Bottom line, the healing power more then doubles your heals putting them just below the level of your self heal, it's worth it. I really don't think 4k extra health is worth it when I can heal that same amount of hp with one empower.
You can still get a lot of boon duration as well with the runes you suggested and the right traits, getting the best of both worlds. That is how I run my guardian anyway.
Other then that very good guide for someone looking to understand the essentials of a guardians job.
Edited by Senatic, 16 November 2012 - 02:07 PM.