Wardens - Nature Walk or Shatter Infection?Follow

I've maxed out the points in my EoF Warden tree and respent the points a few times now. I'm wondering how much luck my fellow Wardens have had with the Nature Walk and Shatter Infection abilities. All of our final AA skills are so situational it's not funny.

I tried Nature Walk for a while. Immunity to root and "most" knockback effects. "Most" knockback effects is pretty vague. What it really means is your group is immune to almost "NO" knockback effects. Any named mobs will still knockback. Any epic mobs will still knockback. Every time I turned around I was still being thrown against a wall. How many mobs do you know of which have knockback, and aren't named or part of a raid?

So now I've just respent my points to get Shatter Infection. For those who don't know it grants a 30 second buff that cures groupmates of all hostile effects if they drop below 25% health. 3 minute recast.

I haven't gotten to use it much but when I did in a situation where I thought it would help, it didn't seem to do anything because the hostile effects came right back. Also the 2 second cast is too long, IMO. It doesn't seem that way at first, but the spell only works for 30 seconds on group members that have dropped below 25% health. I don't know about other Wardens but when I believe my group is about to drop below 20% health within the next 30 seconds the last thing I want to do is waste 2 seconds casting a spell which MAY cure some hostile effects instead of using that time to cast a group heal.

Shatter Infection seems like it might be useful IF the cast was instant, or perhaps it cured all hostile effects if someone dropped below 40% or 50% and KEPT them cured. Also if the dumb thing lasted more than 30 seconds. I wouldn't even mind it if they upped the recast to compensate.

For the 21 points I spend to get the ability I would rather just have a group cure trauma/arcane/poison/elemental spell with an hour recast.

Have any other Wardens had any luck with these two abilities? Has anyone found Shatter Infection to cure "incurable" effects or stuns? That was my initial hope when I spent the points.