Hi, The dinghy is a hard-bottem RIB: Brig 330. Engine is 20 HP. Total weight with engine is 150KG. I lift her whit Davids on the back of the boat and never put off the engine. Very easy and fast.
A good dinghy alows you to anchor further off (More chain, more space, more security).
In Norway, engine has to be less than 10 HP or else the children won't be allowed to use it. So we have a 9.9 HK engine (in reality it's a 15 HK engine).
Oh, the rules also states that the boat should not be able to go faster than 10 knots. I think ordinary march speed on the dhingy is 20 knots. Details, details ...
Our david is dimensioned for lifting a simple rubber boat without engine. I believe it's physically possible to lift up the RIB with it, but some few small waves and the whole thing will be destroyed, hence we always tow the RIB.