We’ve spent most of last year doing heavy customization of a 2.0.15 CS-Cart based site. We held off on 2.1 to wait until it was more mature. However we did such extensive mods we are thinking of just staying on 2.0.15.
What are the top fixes/improvements in 2.1 (or issues in 2.0.15) that we should consider trying to address ourselves if we remain on 2.0.15? Another way to think of it is if you were stuck on 2.0.15 and you could have any 5 modifications/fixes, what would they be?
Do you have a sense of just how many improvements have been made between 2.0.15 thru 2.1.3, here is a hint: ALOT 
Doubt you will find anyone with time or inclination to write a book, so you might start here:
[url]http://blog.cs-cart.com/category/cs-cart-releases/[/url]
I don’t need to know them all. I’m more interested in what people think are the most important ones.
Ok, here is another “hint”!
Based upon what I have read in your previous posts, substantial improvements have been made to the majority (if not all) of the issues you were concerned with.
Although I talk alot, I actually read far more! 