Hi,
Yes, the Virtualcol DHC-3 Otter runs under P3D4 quite happily.
When you buy (if from Virtualcol), do download the DHC-3 Otter update from your account.
To install, just create a new folder somewhere (desktop), and point both installers to it, then simply copy/paste the resulting folders and files into the corresponding directory in P3D4.
I have also found the following excellent thread under SimOutHouse where new CFG file data for both piston and turboprop powered variants is available, as well as new float contact points:
http://www.sim-outhouse.com/sohforums/s ... gine-FixesBUT, this configuration gives a max IAS of 120 kts which is short of the maximum (139 kts), so to the SOH CFG I have added the engine scalar of 1.75.
I can obtain about 143 kts using fuel to tabs and 1/3 payload using this setup, but the good thing is that this is adjusted to max RPM of 2300 with new engine and propeller data; I'd suggest that this is essential.
Also, in the SOH thread you will find references for new VC textures (at Flightsim.com), and these are worthwhile, as are further adjustments in the SOH thread to the turboprops aircraft.CFG and panel.CFG which has been modified to take (better) King Air gauges.
Do note that I have not had time to test the turboprop model as I'm going to be busy for a bit, so I'll leave that to someone else.
With these adjustments, I would say that the Virtualcol DHC-3 Otter is a worthwhile product BUT only if bought at sale prices, otherwise at the present and full price of $14.50 (£10.91), considering the necessary CFG changes and lacklustre visuals typical of Virtualcol products, then remember that Just Flight have just released a DHC-3 and that Milviz have a DHC-3 Otter in the works plus they have just released their highly regarded P3D4 friendly DHC-2 Beaver.
That said, it is a fun aeroplane to fly, it handles reasonably (read slow and lumbering and precisely what one might expect for this type perhaps), has enough variants included for the price, and is cost effective to buy. There are references to one or two nice repaints available for it too, so do please post links to them in this thread if you go looking for them.
Hope this helps, but do let us know what you and how you get on.
Best wishes,
Fabio