In circuit emulators are used for real time debugging/stepping. What do you mean get more preformance out of the chip? ANY part can be socketted. I have lots of Famicoms with socketted CPUs, think they're worth more? lol
Yeah, ICE debugging is about the closest you can get to the metal when debugging. For instance, PC ICEs are used to write BIOSes and wicked stuff. Oh how I'd kill for a X86 ICE :-D
I think its some sort of naming conflict - the assemblers from SN Systems were indeed named SNASM* - such as SNASM68k, SNASMSH2, etc. - but so were their respective kits. I remember the first Saturn kit from SN Systems was also named SNASMSH2.