Plenty of match types seem to buy them. Of the little I've seen of them, they do appear to be a few quality notches above the Preston/Maver/Matrix stuff that's in the £400-500 bracket. As ever though, twice the price doesn't get you twice the quality.
I did have a Preston Absolute Compact ( Prestons meaning of compact is different than mine) until recently,
I sold it and bought an old ASI seat box, this may be a tad heavy,but I can carry it and it has made me realize I take to much tackle to various venues, If I have a match I use my grandsons daiwa SB75,
the Preston and the Daiwa are "H" frame style boxes meaning you can adjust the height of the box without adjusting the footplate,I don't think you can do this with the Rive and also the Map Z frame box that is also around a £1000.
I have heard a few things about drawers sticking with the Rive boxes and catches breaking,
What I am saying basically is that you don't have to pay a fortune for a good usable seatbox,
it will be interesting to see the sales reports of the "new" Shakespeare box when it hits the shops properly.