When I understand your question correctly you are seeking advise whether the Realair Spitfire or the Classics Hangar FW190 is the better buy.
Therefore I won't advise you about a future release from A2A, from which only a picture from the VC exist, a Spitfire release from a few years ago, that you already possess nor a feature called accusim, as none of these two models has it.
Personally I think it is impossible to answer for you which one you will like better. It feels a bit like answering the question 'do you like fish or meat for dinner?' for somebody else.
The Realair Spitfire is in general the same model as the FS9 version. I have always like the model in FS9 and I also enjoy it in FSX. Personally I fly the new Mk.IX more often than the MK.XIV. I have heard some critics about the flightmodel which isn't realistic enough in the eyes of some, but as I don't have any experience with the real thing I can't really judge that. For me the most annoying thing about this model is the loading time from the VC. In my opinion another weak point is the bumpmap. From some angle the external model look really stunning, but a small change in the view angle can make the model look like far too glossy. However you don't need to worry about the pilot. Although the pilot is the same as in the 5 years old FS9 version, it looks much better than the one in WWII Fighters A2A Spitfire MK.Ia. Personally I'm not a great fan from the included sounds....
The Classics Hangar FW190 is a much newer model and you can see that. The VC is by far the best I have ever seen. The gauges are 3D modelled and I absolutely love the Radium illuminated cockpit when you fly it without the VC lights. The external model shows the craftsmanship of the people who made it. I have not heard much criticism on the flight model, so I guess as nobody complains it must be good (but again who am I to judge). However compared with some other FSX models it is quite easy to fly. Not because this is an error in the flightmodel, but just because the FW190 was a very modern aircraft for its days and many things were done automatically.
Both aircrafts have gadgets like programmed engine failure with nice visual effects, when you overload of overheat the engine and both aircrafts were definitely worth their money in my opinion.
Personally when I had to choose one, I would go for the Classics Hangar FW190. And definitely not because I have been a beta tester. (To be honest I have done some beta testing from models which I would not recommend anyone to buy.)
But the FW190 model is more modern which is definitely visible and especially in the VC. The FW190 has some features which the Spitfire doesn't have like the above mention Radium illuminated instrument panel. Next to that the FW190 package offers more versions (9 for the FW190 (even without counting the different load-outs) against 6 for the Spitfire) and last but not least because Classics Hangar has promised the owners of the early version package a discount on the late version package.
The prices are nearly the same. When you already own the FS9 Spitfire you will be able to download it for 22 Euro, otherwise you will have to pay the full 29 Euro. The FW190 is 29.95 Euros for people in Europe, but can be purchased for 25.17 Euro for people outside Europe. When you like the model on an original CD the Realair model is the only options.
As said I personally prefer the FW190, but I prefer to fly the 'bad boys' aircrafts anyway. I have the WWII Fighters set as well. The Bf109 from the package is completely worn where the Spitfire doesn't yet need its first overhaul

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Cheers,
Huub