There is a review of the gun & discussion of the TriBlock system @ www.oplognosia.com/english/beretta486.php

From the limited info & pictures that have been provided by Beretta it looks to me like the TriBlock system combines some features of both shoe lump & dovetail lump construction.

I did have an opportunity to handle both an English grip/splinter FE & pistol grip/Beavertail FE gun @ the NRA Convention & my impression of the 486 Paralello was that it is a nice step up from the 470/471 guns in fit & finish and appearance.