[simonator]

The low latency talked about with Carbon and HDX is solely based on using DSP plugins, then you get to the sub 1ms they talk about. That’s great for live instruments / vocals etc….

There are some DSP amp sims out there - I think Eleven Mk2 is an example - that will absolutely benefit from the Carbon Hybrid engine, but again, only while you’re recording and have the live track in DSP mode.
Sending an aux to a reverb or delay in DSP safe mode will bring back the system latency to those plugins, so if you’re at 64 samples that adds another couple of milliseconds.
With any other non-DSP mode plugins, you’re still at the system latency.
I never get near 64 samples, the benefit of Carbon is that I can have loads of things running, and still be able to overdub a cowbell at sub-ms latency in the middle of a complex session.

I had an HD Native card, I got Carbon. What I can recommend in addition to the low latency performance is (a) the sound. It sounds really excellent, and the instrument input is great. (b) the dual engines which allow me to run core audio in parallel (c) Carbon’s performance for me with VI’s has been (guesstimate) 15-20% better. YMMV.