Obviously, the sliding compression tube is best. Decades of match wins by the FWB 65, 80, 300 and HW77 and AA TX show that.

I do like the BSA RB design. I don't think they executed it well. I'd prefer a catch that was less likely to foul a long scope, and auto-opening.

And there's a lot to be said for the taploader.

Yes, there's an unswept volume issue. They will never top the efficiency chart.

Yes, many of us have experienced alignment and other QC issues on things like 1970s Airsporters.

But a good tap-loader, like a BSA LJ pattern, Mk1-2 Airsporter, Webley MkIII, pre-late 60s Diana 50, properly lapped and aligned by hand at the factory, is still a great thing, easy to use (esp with auto-opening), pretty accurate, and very, very, safe.

Sure, no tap-loader will win the FT World Champs, but for general use, a good (good) tap-loader remains a perfectly decent rifle.

The same might apply to pop-ups. But I have never owned one (unless the Gamo Spring pistol rotary breech/tap counts), and just don't like them, for entirely irrational reasons.