I`v spent (wasted) more money than I care to dwell over on roofs, some expensive (Zeiss Fl) these last 10 years, I kept them a while and then sold them on always looking for whatever it was that was missing in the view for me.
Then on a whim a couple of years ago I picked up an 8x30 Optolyth Alpin and BINGO, there it was, that amazing like my own vision 3d view of the world, how could this humble old optic please me so much more than an Fl ?, well it did and I started to seek out the best in birding porro`s still around SE/EII.
I`v little doubt the SF will be outstanding in both optics and handling just like the other Alpha`s but those humble porro`s give me the greater satisfaction thus far.
Curiously, some people, Henry, for example, find the porro view unnatural! I can understand that at close focus where the view from both barrels can overlap and you have to cross your eyes slightly to stay focused on an object, but at medium to longer distance, a porro's view, to me, looks more natural than a roof's.
I don't recall Optolyth offering an 8x30 model in its current line of Alpins, so I went to deutscheoptik.com to make sure, and I found they no longer sell the Alpin series. That curious since the owner of Deutche Optik was the one who persuaded the "new" (then) owner to reissue the classic porro series. They still carry the Royal roofs.
I tried an Opto Alpin last year was not that impressed. I think it was the 10x40 model. It was a lot smaller and lighter than I had expected and the waffle pattern rubber armoring was very nice, but optically, I'd have to say that even the Nikon Action EX was better, and it costs a fraction of what they want for the Alpins. It didn't have any major distortions, b but the resolution wasn't as good as I would expect from a fairly expensive porro.
I've also bought roofs over the years and tried others including Swaros, and while there were a couple I really liked - 8x32 EL WB and 10x42 SLC-HD - the SE and EII are at least as good, IMO, and provide a way better bang for the buck.
But in the winter and for "iffy' weather where there's a mist or light rain, I wouldn't mind having a good quality roof to use with impunity. The problem is that the SE and EII spoiled me. To get as good a view, I'd have to spend multiple times more.
Brock