[propower]

If you track with all TDM plugins on the record enabled channels (no native on these - elsewhere is fine) your latency is ~2.4ms today to the artist (no dependence on buffer). If you moved to HD Native and track at 128 with an AVID I/O you will have ~7.2ms. Other converters won't help much (as I already detailed above). The DAW buffer is already 256/48k = 5.33ms. Whether this is acceptable or not for you is all up to you.

I will add that at 44.1kHz the AVID I/O is 1.9ms A/D + D/A time. Many other I/Os are actually much faster at 44.1 and are more like 1ms (lynx Aurora comes to mind). This will certainly help. But if your buffer is truly 128 then 6ms - 7 ms RTL is not much difference to me (both pretty high).