As a rifle, the Sako Quad is excellent. I've got a synthetic stocked version in .17hmr. They're as good as or better than any other similar rifle.
The swap-ability of the barrels is another matter. Originally, you were able to get a scope (can't bring to mind what make it was just now) where it supposedly did away with the need to zero every time you swapped barrels and it was all thought to be a jolly good idea. In practice, most people found it a chore to keep changing their barrels and magazines every time they wanted to change calibres. So a lot of people simply got another rifle to cut out all the faffing around. They then just had to grab the rifle of choice from the cabinet. I understand that was one reason they discontinued them and re-invented the Finnfire.
If you are short of room or for some other reason need a Quad with two calibres of choice, fear not, they are a good rifle. But I'd worry about the zero and probably, like many, I'd end up just using the barrel that was on it. My advice would be to get two rifles, even if you get one now and save up for the next one.