@RobDeckert Sorry for the late response, I am not on the forum much. I wanted to redirect back to this thread as there are other posts here that are as equally helpful.
I’ve been doing this for about two years now and I am still learning and playing with feed and speeds. There really are a lot more components than just Depth and of Cut and Feed Rate and much of it comes down to your machine and your needs.
I do a lot of inside cuts that can’t easily be sanded so I want the best finish I can achieve. This naturally means slowing down. However, if I am doing an outside profile cut, like the perimeter of an object, which can be easily sanded I might bump up the speed a bit.
Point is I can’t answer for your needs and your machine.
For me I have found that the CMT hardwood 1/4" spiral gives me the very best finish. I have been really happy with their bits and that really is step one- find a good bit. On my X-Carve it seems like .06 DOC at 60 in/min gave me a really clean finish most of the time. But I did the x and y mods to stabilize my machine.
I don’t use the X-Carve anymore however, but even on my Stinger 2, though I could easily do a full depth pass on 1" hardwood, I cut about the same speed but at .25" per pass. It takes longer to cut but minimizes labor post cut, which is very important.