Thinkpad X300 has a 2Ghz processor, so it’s faster than an MBA.
X300 is lighter! 2.5 lbs vs 3.0 lbs
X300 has better screen resolution.
You can add memory to the X300, not to the MBA.
You can swap out the battery, not on an MBA.
X300 has all the usual ports, then MBA does not.
X300’s battery life is longer than the MBA’s.
Both fit in an envelope though.
Hmmm. Well, I haven’t touched a PC with Windoze since 1990, so, it sounds nice but not for me. Hack one for OSX and you got a winner! (I especially like the GPS, extra memory and optical drive.)
And it'll shorten battery life.
X300 is lighter! 2.5 lbs vs 3.0 lbs
True, metal weighs more.
X300 has better screen resolution.
I consider that a disadvantage. LCD displays look good only in their native resolution, and when readability suffers when that resolution is too high, making screen elements too small. Dell laptops are notorious for this.
You can add memory to the X300, not to the MBA.
True, and it goes to 4 GB, which is the sweet spot for Vista. The MBA comes with 2 GB, the sweet spot for OS X.
You can swap out the battery, not on an MBA.
True, also a function of size, and the lighter weight will include not having your optical drive or extra battery installed.
X300 has all the usual ports, then MBA does not.
It's much smaller than an X300, no room to put those ports.
X300’s battery life is longer than the MBA’s.
It isn't even out yet, so that has not been confirmed. Do not expect more battery time with that faster processor compared to an SSD MBA, which does hit five hours.