I don’t power play so this is just from forum chat and stats.I considered getting the Prismatic Shield, but everything I read about it said it wasn't worth it - that even though they're tough, you basically have to dock to recharge them because even with engineering it can take upwards of 5 to 10 minutes for them to recharge to 100%.
I see them as potentially useful for an explorer or trader that wants better protection than using the smallest shield slot would provide. The recharge time shouldn’t be a factor in single fight encounters so I assume handy for assassins.
Then of course there are tanked cutters.
But as with everything it comes down to what works for you and your playstile, the cost mass and recharge times wouldn’t make me that fond of them but even if they were a lot better the power play aspect would still put me off.