I don't pay attention to the new exchanges unless there's a coin that I hold and its listed to that new exchange. But that's not all, I'll check if the volume there is quite good but if its totally zero, why would I'll waste my time trading there?
The security shall always go number one concern but don't trust it completely to the exchange. Be a responsible trader not only with your trades but together along the way you keep your records. We are also the one that must be liable and vigilant to it though the number one concern should really go first. But considering what's good now is easy, if you'll just echo with the crowd.
Yes youre right, its not good to pay attention to all as long as youve got the tested and trusted ones. The only time one can choose to go for another exchange is when they are holding and they find out that it is listed on a new site which they would like to trade. And before you go for that new exchange, its best to make a lot of research about them and even read reviews online about them before considering it as an option.