One of the things about photos on here is that they're invariably done macro-style and make things seem bigger than they are. When I first saw the Arrow amp in real life I had to laugh because it was much smaller than photos on here had me believe. I guess it depends on your definition of portable. The 801 isn't something that's going to fit in your trousers/pants (unless you're wearing cargos), but it's still portable in that it'll fit in a small bag and can be held in the hand, or a larger coat pocket. Indeed looking at the 'Show Us Your Portable Rig' thread, many people have set ups that clearly require something other than a trouser pocket.
I'm not a fan of stuffing my pockets, or think that strapping a small bag over your shoulder robs you of your masculinity, so portable to me is anything that can be carried comfortably and used without needing a place to set it up .
Anyway, on topic. Interesting. I know for a fact, night and day, that my S:Flo2 was blatantly better than my iPhone 3GS (with the same mid-range IEMs) and would be
supremely confident anyone else would be able to tell the difference themselves, as it wasn't subtle, it was obvious stuff, e.g. using a dubstep song with very low sub bass, it wasn't even audible on the 3GS but clear as day on the S:Flo2, less veiled sounding overall,bigger soundstage etc. Several other owners considered moving to the 601/602 an upgrade in SQ (e.g. Anaxilus), although they may be kinder to IEMs and IIRC many 801 owners who have IEMs use a portable amp as well (which is ridiculous given the 801 is meant to be an 'all in one').