I've waxed wroth about them in the past, but I'm coming around on them. My main problem with them was that they kept burning out --which voided out the benefit part of the cost-benefit relationship.
I guess once you get through the crappy ones, the rest seem to be OK.
My problem is, as stated above, the removal of the freedom of choice.
And frankly, I'm getting a little tired of companies making it a matter of law to use their product exclusively.
Let's face it, one of the tenets of free-market competition is to eliminate the competition.
Once that's done, the price = demand / supply equation goes all funny.
Or goes all tragic --your preference as to terminology.
Terry, 230RN