So ... as above, do I need to disable ESD to ensure that latency is not affected? Does ESD have any effect on latency at all?

I don't have any special hardware - only onboard audio (nForce 405 MCP61), which gives me 8ms latency with consistently zero xruns. My typical setup includes running Jack, QSynth, and Rosegarden with my MIDI keyboard.

I have previously turned off ESD before for fear that it will interfere with Jack, but I recently turned it back on and I can't seem to hear any obvious, difference, however I do feel that the keyboard response is more sluggish (more latency).

I can't verify this for a fact - I don't really know how to measure latency in setup like mine, so it could simply be a psychological effect.

Any comments from the more experienced?

Oh yeah - thanks for the great software which is 64studio! I'm running 2.0, 64-bit.