Hey OP
Do you still have your MBA? If yes, are you using it as your primary machine? And how instant are slider adjustments when you are working in the develop module of LR with your 36mp RAW files? I'm basically wondering if the MBA has enough grunt for LR and 12mp or bigger RAW files?
My personal situation is similiar to yours: I have a 27" iMac (Mid 2011) and an iPad 4. I also use LR 4 to work on 12mp RAW files.
I'm considering to get the new 13" Haswell MBA with 8GB RAM and the i7 CPU as my primary machine. I'd sell the iMac and iPad but also get a TBD so I'd still have a proper screen for editing.
Any input would be very welcome.
No, I do not have my 2013 MBA anymore. I returned it within the 14 day period since the Photoshop flicker was an issue at the time and didn't want to be "stuck" with a new machine that flickered when using photoshop. According to Adobe and Apple updates, that issue has now been resolved.
As far as Lightroom was concerned, it performed wonderfully. The sliders would adjust in realtime and editing was a a delight. The screen is also what made my decision easier for the return. I am now waiting for the Retina Haswell 13". I'm sure it will be a way better investment for the dollar value. My notebook is NOT my primary workstation. I have a 2010 Mac Pro that I have been using since its release. However, I am also changing from my Mac Pro to a Windows 8 PC that I'm building. After finding out what the 2013 Mac Pro's are, Apple isn't giving me what I'd want in a workstation anymore, primarily that fact that they are pushing Thunderbolt, which is at this point a huge investment on its own.
If anyone is curious, my system will now be:
Primary Photo Workstation:
Intel 4770k 3.5ghz Quad Core(OC'd to around 4.2-4.6)
32GB Ram
2x Samsung 840 Pro 250GB SSD's
EVGA 770GTX 2GB Video Card
Western Digital 2TB HD
Windows 8 Pro
(Build can be seen here:
http://pcpartpicker.com/user/butch10x/saved/24Qo )
Back Up/ Storage will be a Synology Diskstation setup
Mobile Workstation:
2013 Haswell MacBook Pro Retina
It was a tough decision to move to a Windows based system, but frankly I'm very disappointed that Apple is putting out a Mac Pro that isn't very much customizable. Once I complete the build and test out my workflow, I will post here my thoughts and experiences.