Which mod you go off of depends on what you want
LoR went off in an entirely different direction. I just didn't like where it went- but it's a good mod.
Merged Mod I think is closer to Wolfshanze's idea, though some things are different.
Wolfrevolution is Rev mod tacked on to base Wolfshanze.
Just to give you an idea of the differences.
I don't think I could play Civ IV base without Wolfshanze's work though. Hopefully on Civ V someone tries to recreate Wolfshanze ASAP.
In my first foray into working with mods on this deep of a level, I actually merged the Next War and Wolfshanze mods together. The German text on the German and Austrian UUs is not displaying properly and I had to removed the gamecore.dll to make it 3.19 compatible. Other than that its working very well so far and I'm enjoying it. I was trapped on an island by myself until caravels so I'm being forced to resort heavily to naval technology to expand. Hoping to get to the mid 19th-century steamers soon.
One critique I have is the galleon's bombard ability. Galleons are mainly transports and something just feels wrong about it on a gameplay level. Say, an invasion fleet consists of 5 galleons with 6% bombard abilities. That's a 30% bombard ability there and combined with the bombardment abilities of your escorts your target city's defenses will fall pretty quick. I wouldn't object too much if the paddle steamer and transport also had modest bombard rates, but it seems to me that with this mod the overall bombard rate of a fleet can potentially DECREASE as the eras progress instead of increase and that doesn't feel quite right to me.
The problem with Wolfshanze that plagued the mod for the entire time Wolfshanze did it, was that most of the cgi was totally unoptimized. Some of the models had ludicrous numbers of polygons, like 20,000 or something. This is a huge contributor to the crashes and late game problems in the mod. My understanding is that the main effort of LoR was to go through and clean up the models.I had a look at Legends of Revolution but there are certain things I prefer in Wolfshanze over LoR.
I absolutely love the Wolfshanze models and all the thought that went into picking them, though yes I have noticed that it tends to run just a bit slower than normal. I really dislike how LoR replaced all the jet fighters with earlier jet fighter models like the F86 or even the Me262. That's just one thing.