Yes it will give you 4-6 energy along with a chance of gaining a telemetry. If you have the slot and time to upgrade it with bounties and such then yea go ahead. And yes I think most of us buy weapons and break them down.
Shards, everyone has a surplus of I think. Energy is a bit more of a need now as weapons come more easily, at least for me. I haven't had the best of luck when it comes to armor in VoG, about 10 HM runs, along with 4 regular runs on my 2 Titans and only 1 pair of gloves, 1 pair of boots, and 1 chest. I did get 5 Helmets, but each one is worse than the one I got from the first drop.