Sorry about my late reaction to this.
I noticed the return of the Brno brand almost immediately when it came out, and tried to get some info. Seems even the importers and retailers are not very well informed about the weapon.
I have not had the opportunity to handle one myself. Only rifle/shotgun combos are available here and I saw no point in handling one.
However, I did exchange some e-mails with a nice gentleman from Alaska who has many old Brno doubles, and he bought the first new one in Alaska becoming the unofficial authority on the topic.
The discussions we had were before the introduction of the .458 stopper so things may have changed.

The older guns were very much hand-made and the fit was excellent albeit the finish not necessarily so: the parts were hand-fitted and well soldered together.
This new model is of inferior finish, and the parts are to a great extend screwed together and there is less of the fine hand-fitting to be witnessed.
The Brno (and CZ, for that matter) barrels have always had a good reputation for accuracy, and the guns are very rugged.
If you're looking for a working double or a "to go" gun that you need not be too careful about, the Brno is probably a good choice.
Also it would probably be a good choice for some further 'smithing and finishing to make a really nice gun for you.
But, apparently, if you're on the market for a beautifully made, light-weight O/U double, the Brno is not the choice.

In brief, the double rifle is based on the O/U shotgun frame and thus switch barrels are available.
The barrels are attached together so that the owner can regulate the barrels himself.
I tried to obtain info on intercepting sears and like, but at least the importer here, though polite, was not able to advice me, and the manufacturer didn't respond to my e-mails so I'm not familiar with all the technical details.

- Lars/Finland