I've seen macro shots and reviews (especially the JOMW one) of the SARB033 as an example and can say the main differences are in the case fit and finish and finer detailing found on the Alpinist SPB259J1. Even under Macro it's very hard to see any cheaper finishing on the Alpinist. Both the SARB and SPB25911 have the same bracelet it looks like and whilst it is comfortable, it offers basically no micro adjust and has pin and collar for link adjustment which I don't like. I am not a fan of bracelets anyway though.
I fully imagine the SPB259J1 would have been around the £550 mark had it not been a 140th anniversary limited edition. The dial is in a league of its own though and no SARB can compare even remotely. The lume is better, the hands are better, the applied markers are more striking, the crown is grippier, the water resistance is doubled but as a by-product the case is slightly thicker at 12.9mm vs the 11.9mm of the SARB and there's an AR coated single domed sapphire crystal too.
Having bought a lot of watches over the years in the £500 to £1000 range I think the £670 rrp is very reasonable for the quality finishing and details you get. The only two things I'm not a fan of are the movement deviation depending on positional wear, and the bracelet's lack of adjustments although both of these negatives are things Seiko has been famous for going on many years now in the mid-range segment so it's kind of expected. Hell even their Grand Seiko bracelets aren't all that for features either.
For me it's all about the tropic strap and dial alone. Edit* Just look at it!
