The features are as follows:
Now these are lighter than the standard Marathon (that I actually have on all my Brompton bikes and rate very high) and do have 'Raceguard' that offers good puncture protection.
A nice tyre, that is very useful as a spare as they can be folded, but they are only available in a few locations and cost £40 a piece. I think that this is rather steep when you consider the ordinary Marathon Racer (which doesn't fold of course) can be bought for £22 or less.
The only other tyre out there that looks like these are the tanwall Kojak ones - that cost even more. For me, I will be sticking with the ordinary Marathons!