It's Moltke+, now with extra freeboard (and speed!)
Seydlitz was the final iteration on the Moltke design with a little bit of added length and even an extra forecastle deck. She larger, faster, and tougher. Seydlitz won the distinction of most durable battlecruiser of WWI, coming back heavily damaged on two occasions.
The Seydlitz has the same gun arrangement as Moltke, with the added bonus of being 4.5 units. This gives her the possibility of a 75 round haymaker with a second haymaker and stern gun in the wing turret. Devastating!
Charley took this one step further and bravely mounted a 1/2 unit pump and set her up with twin sterns angled at 15 degrees, a haymaker and a bow sidemount. This configuration turned out to be downright vicious, if a bit on the fragile side.
Altogether, Seydlitz has excellent firepower for a battlecruiser.
Seydlitz is the shortest 24 second battlecruiser. 'Nuff said. Combined with four shafts and relatively light weight, she accelerates quite well, too.
With the same tandem rudder arrangement as Moltke, Seydlitz doesn't have the same maneuverability as a twin ruddered ship like Von der Tann. However, the rudder area is the same, and is enough to make her turn quite well.
The Seydlitz has an extra forecastle that the Moltke doesn't, but at the same time, when running at combat weight, her aft deck is nearly awash, and her middle deck doesn't seem to have much freeboard either. Additionally, in the casemate area, the proximity of her armor belt results in very little area to shoot a bb through.
Seydlitz is a ship of extremes. She has the potential to be extremely poor, so she is much less than ideal for the beginning battler, but in the right hands, watch out. I think Charley and Austin pretty much conclusively proved this at the 2016 Nats.
I liked it so much, I bought the company, or at least the boat. Yes, I now have Austin's Seydlitz. Hopefully, I'll get to battle her next year, at a regionals or two. BC's kit is excellent, and I wouldn't hesitate to recommend her to someone who wants a killer battlecruiser.