We had this argument a year or more ago, and you KNOW I prefer monitors
No, I DO not know, That does not mean I did not know, but at our age it is legal to forget.

I prefer monitors for their real-time capabilities over ICE's
I do not know of any "real-time capabilities " that ICEs do not have.

I'm sure you've noticed that JTAG isn't capable of reporting what's going on in dozens of registers in real-time, so you have to hook up your logic analyzer and go to work. I'd rather do that with a monitor than a $50K or $5 piece of hardware that contains someone else's compromises.
I know of no "monitor" than can "report what's going on in dozens of registers in real-time" one characteristic of a monitor is overhead. However, some of the very expensive ICE variants (which I have used when working for "rich" companies) gives you what youn describe and does it in real time.

Moving data into RAM is handy if you modify it several times before writing it back into FLASH. I'll grant you that one, but that is rarely a time critical operation.

Erik