The Moltke was Germany's second battlecruiser, and added a second superfiring turret on the stern for more firepower, and a lengthened forecastle deck for better sea handling. Her sister ship Goeben had a very adventurous career in the Mediterranean, and later in the Black Sea as the Turkish Yavuz.
The Moltke offer something that the Von der Tann most definitely does not have - a raised X turret. As a result, she can carry a well down angled haymaker, and with the wing turrets, can mount the dual haymaker with stern gun setup.
For the less adventurous, she can also mount a more standard configuration.
Overall, I would personally prefer the two haymakers...
At 26 seconds, Moltke has good speed. With 4 shafts, and decent weight, she also has good acceleration.
One thing that Moltke does not have is twin rudders. She does, however, have inline rudders, but this matters less now that all ships get the same rudder area. Her maneuverability is good, but not great.
Another issue that Moltke has is that she has a forecastle deck that runs the entire length of the ship back to X turret. The result is that she has significantly more area to shoot at than Von der Tann. This isn't so bad, especially as there are casemates to mitigate the added freeboard, but it is definitely something to consider.
Moltke is, in my opinion a bit tougher on a beginning battler due to her battling characteristics. The build should be about the same, but on the water, Von der Tann's better maneuverability and reduced freeboard make her a much more user friendly ship. Her stern heavy gun configuration does mean that in the hands of a skilled battle, she can make a very mean boat, especially in "Mexican Standoff" type situations.
I'm tempted to give Moltke a C - Mehbote, but I'm finding it really hard to. I remember Lief's Moltke from back in the day, and Bray's Goeben/Yavuz, and they were both tough and effective little battlecruisers. They're not exactly my cup of tea, but in the right hands, they're downright effective.