Right now I'm leaning towards getting the Quickstep first instead of jumping straight to the most expensive option (Intruder). I've been through A LOT of headphones and auditioned even more, before ending up with my ciems. I think it really makes me appreciate the "top of the line" much more. Also, headphones like the Creative Aurvana Live and Philips Citiscape Uptown have taught me that good things sometimes come in very reasonably priced packages. Same goes for the Clip+ and the O2 amp.
The same friend who had the SR71B also had one of the older Meier portable amps. Can't remember the name right now. Wonderful, sound. Fantastic amp. It was on my target list as well. I can't wait to hear your impressions.