Thanks for posting that - it's helpful and informative.
One quibble - there is roughly a 20% performance differential between the the new MB and the prior MBA, which I'd agree might not be "huge" but does seem significant.
OP - if you're in the 14 day window, your only choice is a new MBA - the new MB won't be out until April 10, which is more than 14 days away.
That's true, though I tend to find a Passmark score of 3000+ is 'acceptable' performance in real-world benchmarks. Basically anything above that number doesn't matter as much as it would, say, with a score of 1500 (mobile Core2Duo).
IMHO, any bottlenecks you'd encounter in real-world performance from the chip in the MacBook would be offset by the speed of the SSD & 8GB RAM at a higher MHz than previous gens. And as the mobile processor in the MacBook has a
much better benchmark than I'd expect from a 1GHz CPU, I really think it'll perform excellently.
To put it in perspective, the quad-core i7 in the 15" 2011 MacBook Pro has a score of about 5500, (which can easily be beaten by a newer gen dual-core mobile i7), so the leaps and bounds Intel are making with each generation is quite staggering once you look at the bigger picture.
Typically on Macs you'll rarely encounter a CPU bottleneck unless you're running heavily-threaded applications - for instance, Logic Pro 9 with a wealth of plugins. Most users will encounter a bottleneck with the RAM or the HDD first. For anything up to light Photoshop work, I think the MacBook will run as well (if not even a little better due to the amount of RAM) than the 13" MacBook Air. Once you get to anything CPU intensive though, you'll definitely feel the pressure of the CPU; though when you reach that level, the MacBook Air wouldn't really be powerful enough either.
TL;DR: if you can afford it, it's my opinion that the MacBook offers as good performance as the MacBook Air in 'real world performance' - other than the examples stated above - though historically I'd suggest avoiding first-gen Apple products until either the price comes down or they resolve any issues with manufacturing (if there will be any).