No I don't think its a big deal, as it is mostly used to avoid skyfall and explosions on the ground, 40% is working just fine for that. The damage from it from Momentum is basically just a bonus side effect, there is plenty of damage elsewhere. Ultimately though, I WOULD prefer a pet with Zealous talent on it to cap it.
If you are building and happen to get it, I wouldnt just throw it away though. Take what you can get as you can get it.