Me too - Nero 8.
ImgBurn is largely useless to me because it doesn't support multisession discs (and quite a few other things).
The software makes no difference to writing quality.
Not unless it is so buggy that it interferes with the writing process (e.g. continuous buffer underruns) or gives access to certain drive writing features (which can be set using separate utilities anyway).
I certainly wouldn't call running 32-bit software under 64-bit Windows 'emulation'. Nero are using the term incorrectly - it is not emulation, the processor still supports 32-bit instructions natively.
Any modern software should run as well under 64-bit Windows as it does under 32-bit. That's not to say everything does, but it should. (Drivers are different matter however.)