I bought this direct through Nemeth when it released. Glad to see it here!
This addon is absolutely worth the money. There are some small issues that Nemeth may want to address that I'll cover, but the short story is that this Yak-18T is a very nice model that is wonderful to fly.
I only give this 4/5 because of the lack of opening windows/doors and the occasional sound looping on the engine which can get annoying. Otherwise it's an easy 5/5.
The good:
The 3D model is very nice inside and out
The night lighting is simple but very visually pleasing
The aircraft is ILS capable
In game checklists are very robust and helpful
Engine sounds are unique and good, though they do have a loop at times (see "the not so good")
Flight modeling feels superb, I have no complaints about the FM at all
The not so good:
Engine sounds do have an audible loop at some settings despite being good sounds.
The in game checklists do not feature focus, so you will have to hunt for some switches the first time around.
Windows and doors cannot be opened
The aircraft always starts with all non-essential switches ON which is annoying as the checklist has you turn them OFF at the end of each flight.