I’ve done some heavy comparison between the two DAWs on my 2012 6-core Mac Pro. Logic Pro X does not feel as “responsive” at times (start-stop, scrubbing, etc), while it does have much better low-latency performance (ie: recording VSTi easily at 32-64 samples). Cubase may not be able to keep up with Logic in the low-latency dept., but for my workflow, it is much, much smoother to use in day-to-day operations. (Not mentioning Cubase blows away Logic when it comes to advanced workflow options) Cubase’s draconian copy protection scheme keeps pushing me towards Logic, and I’d really like to switch… but Apple is not quite there yet…
There’s more to measuring performance than seeing how many hundred reverb plug-ins you can run at one time. 