Gamo has owned BSA for about 20 years. To their credit, Gamo left them alone for the first ten years before decimating the historic company and incorporating some models into their own inventory. Plus, they still use some of BSAs fine barrels. But the days of John Bowkett designs, walnut from Custom Stocks, and, polished blued steel are gone forever.
I haven't seen a real decline in performance of the actual gun. I recently shot the new r10 and it's still a good gun.
My Buccaneer has a split personality. On one hand the barrel is super accurate and works with several different pellets. On the other hand, the fill valve is the cheapest plastic piece of crap I've ever seen and doesn't even have an O-ring. It's a constant battle to get it to seal well. I assume it's the same as the Urban fill valve as it's the same action with a longer air tube and barrel.