The difference between the two rifles... I am not going to tell you of all the bad comments about CVA. They are on line, you can read them for yourself. There were quality issues and whether there still are I do not know.
I own several CVA rifles both traditional and one inline rifle and it is a good shooter without question. BUT, I never push it to the max loads it claims the rifle can handle. I guess that is the deal I made with my head that makes me feel safe.
CVA/BPI (Winchester, New Frontier, etc) have good customer service.
I have used the BPI customer service many times. Some rifles more then I care to mention. But they have always fixed the rifle for free. All it cost me was shipping to send it to them. My grief is, why should a new rifle need to go back to the factory as soon as I purchase it, for something that should have been checked at the factory... Maybe they have quality control issues?
I also own several Thompson Center rifles, traditional and inlines. Without question they are a great rifle. Their customer service is excellent, although seldom used. I had to send in a rifle once. I broke the stock and they replaced the stock for free. My fault the stock broke, but they still fixed it.
I am not into the changing out barrels on rifles but if I had to choose between an Encore or a Optima that would be easy. The Encore hands down. The Encore is a very highly recommended rifle. They are accurate, easy to care for, just like I am sure the Optima is. After all, the Optima was based on the Encore design. Thompson Center is the leader in rifle design along with Knight. They make a rifle, it sells great, and every other company makes a somewhat copy of the rifle.
Like I said, I am not into changing out barrels because I no longer care to hunt with center fire rifles. I hunt everything with a muzzleloader. Also I do not like the Encore/Optima design of the stock. I have no reason why. I like their looks, but do not like the way they feel.
Good luck on your choice. I guess your pocketbook will be the best judge of what you want in a rifle..