1. Initially I installed the 32 bit version of Capture NX2 in order to use the plug-in Color Efex 3.0 for NX2. Recently I installed the new 64 bit version of Color Efex 3.0. Should I now install the 64 bit version of NX2?
2. I recently saw a comparison of Color Efex 3.0 vs. Color Efex 4.0. Color Efex 4.0 was clearly better - smoother, much less grainy. So, is Color Efex 3.0 for NX2 the same program as the regular version of Color Efex 3.0 - i.e. is the same graininess visible in CE 3.0 for NX2 or is it more like CE 4.0?
Yes you want to install the 64 bit version of Capture NX2, it is great as being faster and no more freeze-ups. Just run it again and when you get to the: do you want to run the 32 bit or 64 bit choose the 64 bit and your good to go.
Now I have not seen the comparison between Color Efex 3 and 4 but only Color Efex 3 will work inside of capture NX2, Color Efex 4 you have to export outside of Capture and then import it back in. I hope in the future Nikon and Nik get together so we can use Color Efex 4 inside Capture like we can with CE3.
If you would rather use Color Efex 4 and dont mind exporting and importing back to Capture, then get and setup the Edit List so you can export from right inside Capture as it makes it a lot easier that way. It is free and you can use it with all the software like Nik, OnOne, Topaz, and even export to Photoshop if you have it. You can setup twelve different software applications to work from inside the Edit List. I hope this information helps you out and is what you are looking for.
I forgot to ask if you have version 3.004 of Color Efex 3, if not you will want to download and install it first. It is for the 64 bit version of Capture and is on the Nik website. I din't uninstall the 32 bit version of Capture, I just install over it. But it will ask you for your code again with this 64 bit Capture upgrade. You shouldn't have a problem.
I think the most interesting comment in that article was almost all the other filters appeaered the same between CEP 3 and 4. Since CNX2 version of CEP3 allows direct manipulation like any other edit step in CNX2, I have always used that capability within CNX2 to make the application of the tonal contrast filter more controlable, by making use of the various selection options and making adjustments to the areas of application or their opacity. So I think what the author demo's between ver 3 and 4 could be obtained with CNX2.3 and CEP 18.104.22.168.