Well if built on it’s own without referring to any references the Trumpeter kit will build into an okay kit of the sFH18 but if you want any degree of accuracy both in dimensions and detail fidelity then the Dragon kit is the way to go.
The Trumpeter kit has excessive pin parks and the lower carriage dimensions and wheel base are a worry but it will look like a sFH18 if these are not of concern with these issues partly hidden by the wheels. The kit is also optimized towards the travel position with the limber attached as some parts that only fit in travel mode and the trail arm firing position is not even shown in the instructions?
The fact that both kits miss the lower lip on the gun slide is quite bizarre to say the least given this is a major feature of every gun/howitzer but is fairly easy to add on both.
Assembly of the Dragon kit is simpler but compromised by the many errors in the instructions that will keep you on your toes but overall the Dragon kit is the more refined and accurate of the two as well as providing the easy option of travel or firing position.
Dragon rating 8/10
Trumpeter rating 7/10
See the full Dragon sFH18 150mm Howitzer review here.
I will add additional images of the Trumpeter kit tomorrow showing the assembly sequences the same as for the Dragon kit so you can compare these for yourselves.