I've had the SBTi for several days, and my early verdict is
Get it if:
-You prefer a matte finish over a glossy finish (probably the most important!)
-You like a lighter weight on your wrist. This is especially useful for going for a run or playing sport, or even sleeping
-You like the 'brushed' look, however subtle it is, its quite elegant
-You will benefit from the free extra year of standard warranty and/or like the exclusive Sport Band that comes with it
Do not get if:
-You want a Special Edition Apple Watch that will stand out as something completely different to the public. Thats the Ceramic, which currently isn't available - Titanium's lustre is much more subtle, and I understand what many people mean when they say "it looks like Aluminium" - well, no, it actually doesn't, they look quite different, but I see what causes people to say that.
-You're accident-prone and likely to damage it - not only are replacement costs steep, the AppleCare+ is also even steeper than for other Watches, for both the plan as well as the service fee
But otherwise so far, first Apple Watch edition, I like it, I love that, how like Graphite SS, it has the effect with lighting depending how light or dark the situation is, it can have two different looks, like a chameleon. It can either take on SBSS' appearance of a full black body indoors (albeit matte look instead of gloss), or it can look lighter in the sun and you see the brush effect. It's neat. Coming from SS, the difference in weight is a very welcome change.