I have built both. Both kits are not for beginners. The prime time is a great looking model but a bit difficult to constrct the superstructure. Lots of filling and sanding small wood parts. Very rare to see a prime time completed. I have built one just like the plans, and also plan to build one in modification with heli pad. As far as the Donzi,, also a very nice looking model and is very impressive due to its scale and size. However, this is also difficult to construct for the average builder. Probably the most difficult is constructing alot of the outer rigging that comes along with the kit. The Mr. Darby is a little less complex and also very impressive when complete. Dumas does not have the greatest instructions. They do give you b&w photocopy of some pics which can be hard to see, and then an instruction manual that is small text and can be hard to interpret exactly what they mean. I got stuck on alot of things. In order to actually complete a dumas kit, you just need to also go with your instict and common sense when you get stuck. This web site is also a great resource. There are lots of posts on the donzi, but have not seen too many on the prime time. Good luck