for new slim imac, better just to go 756ssd or is the fusion drive just as good?

will be using new slim imac for only aperture 3 (and my 300gb library) and importing my 40mb photos off my 16gb memory cards (100-200 photos offloaded at a time) and working on a select few and then send them 16bit to nik silver effects so they balloon to 100mb files.

will the fusion be just as good for this?

looking for best performance

thanks