iMac is the main machine and heavy lifter. MBA allows me to move around the house and do light stuff. Also great on travel for email, Web browsing, MSWord, MSExcel and other light stuff.🙂
I have other computers, both OS X and Windows machines, but my favorite laptop ever is the Air. For me it's perfect, I don't need to have an optical drive with me and I can actually get by with the single USB port.
As far as desktops go, the iMac is a great machine, especially at the refurb prices. Of course, it's not the beefiest desktop ever, but it can handle its share.
I'm using my 2.13GHz/128GB SSD as a primary mac also. However, I have a 20" Dell monitor to go along with it, when i need it. Plus I got a blu-ray external drive along with it also. Normally, I'm just unplugged sitting in the kitchen or something
I almost exclusively use my MBA since I got it. I have a work issued first gen MBP that doesn't get any use, and I have a few old laptops floating around that I use for playing around with Linux.
I have a HP notebook running the "oh-so-WOW-vista" home premium
it was actually too slow and sluggish to have a productive feel on it (but even if it feels 'productive', the system lags are still gonna render the machine pretty much 'unproductive' anyways)
and so I got my MBA, use exclusively for all my work and serious businesses (that being said, mostly docs and pdfs, keynotes occasionally)
and since the HP is somehow still booting up,
it's been used as the base machine at home,
but I pretty much do everything on my Air nowadays😛
15" MPB with 24" ACD is the best "mate" for the MBA ...
My MBA is my main machine, I use it whenever possible. Even at my desk with 24" displays I often find myself opting to grab the MBA just because it's so convenient and fun to use.
Probably my favorite "all around" set up was my MBA with a 15" MacBook Pro and 24" ACD combo. Reason being I could have my MBP on my iStand beside my 24" ACD giving me dual monitors and I have have my peripherals all plugged into the ACD.
I had an iMac and used it with my MBA for a while before giving it to my staff in our accounting department. The iMac / MBA was a nice combo, except going that route the only portable option I was left with was to bring the MBA. Whereas with the 15" MBP if I needed to bring a larger screen/more power with me I could. Plus, the advantage I notice of the MBP/ACD combo over the iMac was you had dual displays. Plus, if you need be you could hook up the ACD to the MBA as well.