I do prefer having ADS-B but feel kind of alone knowing that few others are using the system. That said it does make flying out in the center feel a lot safer knowing someones watching me.
I've had other systems mentioned and I think its a great idea for trend monitoring etc but does feel a lot like big brother :P since its only ops who are watching not ATC. I'd prefer it to nothing and if it makes my job safer I'm happy. Also having an Emergency button on it is great.