You've polarized the issue pretty intensely here. A developer using the '10 MBP is not really going to be less productive than one using the '11 MBP. But that's where this logic leads.
I think you're straw-manning the premise. He's not talking about the difference between a '10 MBP and an '11 MBP, more like the difference between a mid-to-high-end '08 MBP running Leopard and a mid-to-high-end '11 workstation running Lion. Try going back to 3-year-old machine for a week, and I think you'll find it's kind of annoying, and your morale will die the death of a thousand papercuts.
I'm typing this on a 3 year-old machine... I'm doing just fine:)
I should elaborate:
I'm running an almost 3 year old MacBook Pro. I do all of my development within VirtualBox (Ubuntu 10.11). I have it connected to a gasp single external monitor. I work every day on a MongoDB/Python stack.
It could be faster, sure... but I'm hardly unhappy with it.
I dunno, man. I do most of my ruby/node/c development on an 11" mba, which is about as powerful as an '08 mbp. Sometimes, I am annoyed by slow test suites, but overall I dont feel the machine is holding me back. If you asked me to work on a windows box, I'd end the conversation politely.
I work on a pretty big C++ project and had a ~5 year old Thinkpad until about a month ago. I can't say that I notice a useful difference. Incremental builds mean that I rarely have to rebuild the entire solution, and when I do, even on the old machine, it's not a big enough deal that I would bitch about it.
I think that for most of us, a few gig of RAM, 2 cores and a 22" monitor (that was my setup last month) is enough that more horsepower wouldn't make us substantially more productive.
Clearly you get diminishing returns here. And in your example you selected the comparison points (MBP'10 vs '11) so high and close to each other that the effect is negligible. jasonkester on the other hand is comparing "crap hardware" and "good hardware"...there the effect is huge.
