It's generally agreed that the Sandwich Technique is manipulative and condescending. If the purpose of a meeting/conversation is to deliver negative feedback, your reports/teammates will almost certainly be able to figure that out. If you're using this technique, I'd highly recommend spending some time figuring out if people actually appreciate this aspect of the conversations you're having with them.
I think the sandwich technique is flawed. Probably not worse than many alternatives, mind, but in my mind it only serves to highlight the criticism. When I notice it I laugh because, well, its the sandwich technique, and this person is trying to be nice when what I need is for them to be critical. I think it has its place where you are giving feedback to many people sequentially to help ensure no one is going to get accidentally picked on. Like when teaching, you don't want to have only negative things to say to the slow student (whose work in comparison will appear even worse).
The 'non violent communication' stuff feels useful as a pattern of conversation when you need to strengthen and clarify your own communication. It helps lead to statements that can't be quibbled with or creatively re-interpreted. Have you ever noticed some one making a big deal out of an offhand remark that wasn't really core to your point anyway? Sandwich technique can't help with that, but the meat of the article does.
Anyway, thanks for the spring board! Hope you enjoy the soliloquy.
I've yet to find someone who like receiving those sandwiches. Only those who give it tend to like it. I work with a nice person who gives feedback in sandwiches. The upshot is no one believes his praise even when given without a sandwich. Beware.
I've gotten to the point where I wince at compliments because of the shit sandwich technique. When I get one, I know I'm dealing with a passive-aggressive person and limit my interactions from then on.