Why not just sub it out when your shadows are gone? Seems like its a very good cape piece to have, sub it out for something else when shadows are down and when doing a WS. If you're not subbing it out when shadows are gone I can see why this piece could cause problems.
There seems to be three good scenarios for this piece. Firstly, NIN or PLD gear swapping it in for provoke, or flash. Secondly, A NIN tanking while shadows are up. As well as it could be very useful for THF for TA (think of endgame pld tanking), as well as pulling with shadows. The evasion and enmity in spite of the critical hit increase can be very beneficial to THF or NIN.
Our lowest hit rate we can reach is 20%, so if monsters are the same the max evasion rate should be 80%, not 95%. The lowest evasion rate however, should be 5%.
One overlooked use is for RDM/NIN tanking and cotanking. Macro this in for your Sleep >> Sleep II >> Dispel >> Bind spam to maximize agro gained.
Though High Breath Mantle is still better in this use as it doesn't add extra chance to be critically hit. Though rdm can very easily hit the -50% physical damage taken cap for when shadows go out on you.
