I got my Vest a loooong time ago. I had to fight, a little, to get it covered by insurance because it was so new. It only took a letter from my doctor and maybe a phone call to get it done.
BUT.... long term wise, it has caused problems. First, trying not to confuse things ahead of time, I got the Vest when I was directly covered under my dad's insurance policy. Now his policy is secondary to my own.
When my dad's insurance was primary, I was first told that our insurance would not be charged. But they were. The cost of the Vest was way beyond my Lifetime Maximum of Durable Medical Coverage (DME, I think it was $10,000). I believe that the Vest company picked up the extra. But, since I maxed out my DME, anything I need now is out of pocket. For instance, an insulin pump is DME, and I will have to pay out of pocket for it (about $5,000).
Now that I have my own insurance coverage, his is secondary to mine. I can use my insurance for DME but if there is any deductible or co-pay, his will not pick it up since my DME coverage was effectively used up. My insurance should cover the insulin pump, but is refusing (a whooole different issue) so I will have to pay the whole $5,000 out of pocket.
Not sure if this is a state thing, or how it is regulated, but the last employer I worked for had GreatWest Healthcare and I was able to get DME coverage for some stuff, which applies to my lifetime maximum. My new employer also has GreatWest. I was worried that the my use of the "Lifetime Maximum coverage" would follow me, but it did not. Since it was a new policy I got to start from scratch and the amounts I used with the previous policy would not count against me.
I suggest you check out your Lifetime maximum coverage for DME with your insurance, and also make sure any promises are in writing. (like how I was promised they would not charge my insurance). Also, if you may be thinking of changing jobs/insurance policies, get your DME purchased before you make the move. That way you can start fresh with a new "allowance".