Tom Smith

So, I've been researching the GTs and am set on that being my choice. Question I have is two fold. Is there a significant difference in the GT Beyond vs GT other than the large price gap. Close to $1,000 is what I'm seeing. I've been on the Yokohama site and from what I can read in English, site is mainly in Japanese, I don't see much difference.
2nd is, there are 5 concave levels. I'd like level 4, but, as far as strength and performance, does the concave level matter?

TIA