It all depends on what you want to see and read. Some will say they are just crappy overpriced screens that show nothing important, some will say they show exactly what they want and are happy to run them.
Your best bet is to look at the specs of each one, use the US manufacturers website for this information not Fleabay, and compare the functions of each one to your needs or wants. Once you've done this buy from where ever tickles your fanny.
I haven't kept up with them since buying mine because I really don't care about a newer model but if you look at the specs you should be able to tell what each one does and which if any does things like EGT.