Athena double is discontinued and hasn't been made since March 2016 apart from a very limited production for warranty.
Athena triple is still made (crankset, braze-on front gear, rear gears and PowerShift levers, silver and black).
There is no interchangeability of Athena derailleurs or levers with Potenza - the pull ratio on the RD is different and likewise the functionality of the FD requires the Potenza LH lever. This is not a "marketing department" lack of interchangeability - the rear shift plain doesn't work if users try to mix and match. Cable recovery in the lever vs rear derailleur movement is different.
If you want to really take advantage of the Potenza front shift, you need the Potenza four-arm crankset. Otherwise the front shift will only be very marginally better than Athena, if at all. You can (optimally) run Potenza, Chorus, Record or Super Record 2015+ cranksets, sub-optimally Athena or pre 2015 but post 2012 other range crankets, further sub-optimally any Campag 2009-2012 11s cranksets or if you really want poor shifting (compared to what you can have from a properly set up all-Campag system), third party cranks / rings that allow a 43.5 mm chainline.
There is no functional difference between the Potenza chain and cassette and their Athena predecessors, which are actually Chorus anyway - but mechanics need to note and act on two things with regard to the cassette - first, there is a revised lockring which is deeper than the existing one - it needs to be used. Second, the tighteneing torque for the cassette is 50 NM - this needs to be respected to avoid damage to the cassette body - hence the greater thread engagement on the lockring. The new lockring is steel, to reduce the risk of damage to the lockring splines at the higher tightening torque.
The Potenza medium cage RD is required for the 32T largest sprocket and is also advised for the 11-29 cassette. The Potenza short cage RD is fine up to the 27 biggest sprocket.
The Potenza brake uses an industry standard shape and size brake block on a holder which secures the block with a screw. The supplied blocks are optimised, naturally enough, for Campagnolo standard alloy rim material (not PEO alloy or carbon).
