As Glenn said: "I don't see any compelling reason to get rid of it until YOU get tired of carrying it around". That's perfectly sound advice. Your Svea 123R will always be a great stove. You have that part down cold and no argument here.

However, it is difficult to draw a well-reasoned conclusion before all the facts are in. If you have no experience with a canister stove, then you have a very minimal basis for comparison. My old Optimus 8R still works about as well as the day I bought it, circa 1974. I didn't get rid of it, because it is still a useful stove, but I now use a pocket rocket exclusively for three season backpacking.

Why did I switch? Simple. The pocket rocket also does what I need it to do, but does it more simply, and it is lighter. These facts do not change anything I liked about my 8R, or make the 8R a lesser stove than it was. They are comparative, rather than absolute facts. I came to these conclusions after I had experience with both stoves.

It is experience that counts most here and your experience will be your best guide - but you might want to use a canister a couple of times to broaden your experience before you make a final decision.