I use an emulator sometimes, not for my main composing, but rather to make sounds and elements from Paul Slocum's Loopcart
www.qotile.net/loopcart
It is incomplete, as in several functions are not implemented, but many are. You can actually make lots of neat sounds, patterns, and etc. with it. Since there is no cartridge version, I fire it up in Stella. I've often wondered if it's "faking it", as in not keeping it true to the chipscene by not using the actual console in this case. I preform my music on consoles, but see the loopcart/emulator combo as an extra instrument, just because it can make sounds and noise effects that the synthcart does not.
Depending on how it's applied, emulators can be useful in chip music in cases like mine. Using it as a minor supplement. I definitely don't think it's cool to come out as a chipper though, and not have or be using the console/system/chip you profess to love enough to make music on it.
--2600