jef – the reason i went for the MBP (not the retina or MBA) was because it was user serviceable. To get the smaller form factor of the retina and the MBA Apple have saved space by soldering memory etc direct to the mobo.
As Rachel also points out above – only the MBP is user serviceable – always research before purchase. The advantage in this is not only upgrades but fixing it if it goes wrong at a later date.
I thought the stock MBP pro was pretty crap before I upgraded it. 8GB is plenty for me as I’m only running one VM, one RDP session, one citrix session and the usual iTunes, Mail (and office 2011), web etc. If you genuinely need 16GB it’d probably melt the table anyway :)
If you’re coming from a windows desktop, one word of warning – MS office doesn’t have feature parity between the win variant and the os x variant. O2011 is very limited in comparison, with none of the nice plugins to evernote, drag to calendar, todo bar etc (unless anyone can point to a reliable applescript)?
(applescript is pretty cool)
Dont get me wrong, i like my MBP, it’s a nice piece of HW, works ok but couldn’t describe it as more stable or faster than a well built win system.