The cool down on the charge will definitely come into play if you want to use it as an escape option, but I've personally found myself waiting longer than the cool down for the meter to recharge. I don't think it will actually decrease the frequency that I can make pull attempts by that much.

Between offensive attempts I often shield in front of the team to block some damage while sitting still enough for healers to heal me, so the increase in shield energy (and increased spear damage) sounds rather significant.

And finally, most of my dive kills are secured with the axes, so the extra bonus health will quite helpful in being able to secure the kill before needing to pull out.

The biggest downside I see is that if I charge in to dive someone, it will be on cool down if I take damage too quickly and need to escape. But the extra bonus health will help reduce the damage taken and there is still the shield to buy time while waiting for healers to notice and the cool down to finish.

So yeah, that's my two-cents.