Well it is no secret that Gredo was designed as a double edge sword and that is good for balance sake. The only thing is that you have to recognize how often it swings back instead of front. Sure it is great against Decimators but the question is what can you put it on. The ideal situation would be B-wing E-2 but that is rebels and Gredo is scum only.
So where can Gredo go, As of now there are only 2 ships that can take Gredo. The HWK and the Firespray. The Hawk only has one shield and putting Gredo on it can often result in disaster (see thread).
The Firespray would be the better alternative but then again compare it to the Decimator. Both the firespray and the decimator has 4 shields, however the decimator has twice as much hull so gredo would likely be flipping crits in equal measure. Worst if you come across Adm Cherenue as he converts a hit to a crit making the first and the last damage card flipped up on you, ouch!
Come to think of it the Scum doesn't have alot of shields at all. After the Big ships with their 4 shields the heaviest small ship shield is the Scum-wing with 3, then the ScumZ-95 with 2. The rest of the ships only have 1 shield.
Come to think of it I see many people talking about putting autothrusters and stealth devices on their skyks and star vipers. I have a better suggestion How about a shield upgrade. Now I know I said putting shield upgrades on unshielded ships like Tie Interceptors is a waist of points (giving my hit crit scenarios) and you are better off with hull upgrade. However on 1 shielded ships like Scyk, Star Viper and Hawks it does extremely better I would suggest that you take the shield upgrade over the hull upgrade. For ships with 2 or more it is a toss up.
So how come I am not seeing any S&V builds with shield upgrades? The Rebels and Imperials might not need it but trust me S&V does.