I'm installing a new store and wondering which version I should install. How stable is 1.3.9d?

I have a 1.3.8 store right now, and had to make a lot of changes in to existing pages and modules to get the user experience I wanted for my customers. http://www.designhousedigital.com

So my 2 questions are:

Does this version have better overrides of the pages and modules?

How well will most 1.3.8 add-ons will work in 1.3.9?

Thanks for any advice!
Mary