I already have a couple of ESV Study Bibles (Scofield and Reformation) as I really like the translation of the ESV, but this is better.
Unusually, it prints the text (in 9pt type) in a single column (like ordinary books) with the cross references in the left margin, and study notes below in two columns in smaller type.
Also unusual (and very welcome) is that it has colour maps (where relevant) on the same page as the text, as well as a map section on thicker paper at the back.
The other bonus is that you get a code number that gives you access to the online text, notes, maps and diagrams; plus you can personalise your notes online (though I haven't tried that yet).
People say it's too big at 2750 pages; but it is more manageable than (for example) the New Interpreters Study Bible (NRSV) which has fewer pages, but in a wider format.
I can see this being THE study bible that others will have to try to emulate.