is it a good time to buy refurb MBA rev. c

B and C are both considered v 2,1. They have the same mainboard and CPU is the same series.

CPU - goes from 1.6/1.86 to 1.86/2.13 (all are SL9x00 Penryn C2D)
GPU - same
RAM - same
Drive - same
Form Factor - same
Ports - same
Appearance - same
Software - same
Display - same

Changes... (other than CPU spec bump), battery bumped a tiny bit barely noticeable to the end user (probably to meet Energy Star requirements), and now includes USB to Ethernet dongle. That's literally it. If it were an actual change at all, Apple would have labeled it MBA 2,2. If it were a serious update including new logic board, or other system changes it will probably become 3,1.

If you want to do more of the higher intensity video stuff, you really need the 1.86 GHz or 2.13 GHz CPUs. Also, the 128 GB SSD really performs exceptionally well versus the HDD.

Both v 2,1 MBAs are limited to 2 GB of RAM forever. Unless you're only buying the rev 2,1 MBA for a year of use, I would strongly recommend waiting for the update to the MBA. It could come out next week, next month, next year, or be EOL'd - nobody knows. I wouldn't advice buying the 2,1 unless you plan to update soon and can get a really good deal on it. Right now, if I had to have a Mac notebook, I would buy a WhiteBook as it's the best current value. I just don't think it's acceptable to pay $1549 for a rev C that is ten month old technology... at $1100, sure. Buy and then upgrade to the real rev c (3,1) when it's released.

Good luck.