Thanks for all the input! I'm going to check out the Schitt store near me today - I might consider the DAC upgrade first since it sounds like the weakest link so far and the Headroom is a bit old on the DAC technology-front.
Re: the store that I went to, it's Shelley's Stereo in Woodland Hills near Los Angeles - they were a close-by Woo Audio dealer so I checked them out. they were friendly enough (and I was pretty close to getting the Firefly) until I ended up buying the MHA100 from Audiogon - I went back to look at stuff for my Stereo/HT setup and they were like "you wasted all our time on your headphone search, are you going to do the same thing with your stereo search?" (paraphrasing). The owner even said "I don't think you're the type of customer we want to build a relationship with" (pretty sure that's a direct quote). Heh What - I note that I went there 3 times and spent ~45 mins each time just going back and forth between their setups (i.e, it's not like I sat there for four hours taking up the store's time, eating chips, watching TV, etc.
). It's just a footnote to this discussion but, yeah, I've never been treated like that and I've purchased relatively high-ticket items (and I tend to go back a few times to make sure I'm comfortable with my decision, especially when I'm spending a decent hunk of change). Anyways, yeah, totally bizarre. Honestly, it all worked out b/c I ended up going somewhere else (Magnolia HiFi) and got talked into an MC452 *AND* 8207 - so I'll take the karma there.