Darkmoon Card: Blue Dragon

I've been wearing this card since level 60, and I haven't really thought much about it. But now I'm seeing some really nice trinkets out there, and I'm wondering if I should be using them. So I've determined just how much mana I get when this thing procs.

The difference between my MP5 inside and outside of the FSR is 305. On average I spend 60% of my time in the FSR, so over 15 seconds, on average I'm regening an extra 549 mana. If I manage to proc my Bangle, this number's a little higher, probably closer to 650.

So is +73 to healing and a proc ability better than 650 mana in a fight? Because usually the card only procs once. So far, I've always thought no. Unfortunately, sometimes the card procs at the beginning of a fight when I'm full on mana. It rarely seems to proc at a critical time. So I'm not really sure if I should grab the Ribbon of Sacrifice, or the Essence of the Martyr, or what. I just don't think that this extra mana is reliable enough. Perhaps having +83 to healing will make downranking an extra GHeal worth it enough to save more than 650 mana in a fight. We shall have to see.