Ignore the bullshit that apple feeds you about the MacBook air coming with an i5 or an optional i7.
This is to fool the unknowing idiots into thinking theyre getting the same hardware as the counterpart MacBook Pro. Look under the surface, and you'll find that this is WAY, WAY off. Apple knows this, that's why they don't advertise what processors are actually under the hood on their website...they simply say it has an i5 or i7. If everybody knew that the Air's came with ULV processors that are basically useless, then nobody would piss their money away on the product.
I'm not saying the obvious fact that the air has slower-clocked processors. anybody can see that.The fact is that if they were on equal clocks say 2GHz-3.2 turbo, the ones in the air are maybe a HALF of the capability that the pro would have.
Now, that taken into account, as the processors actually sit inside both laptops at their OEM specs, you will find that the Air's processor is less than half as powerful as the pro(which is also not all that great, either). A simple way to look at it is that the Air's CPU has a TDP of 15w, while the pro has to dissipate over 45W of thermal energy. Obviously, one is working much harder and creating much more heat.
What I'm getting at, is if you plan on doing anything intensive, the MacBook air is nothing but a pretty fancy paperweight. It's worthless for everything but web browsing and that's it. Even the Macbook pro's are not all that great, but they're twice as good as a MacBook air.
and before we sit here and say "well my air is just as fast as a pro", remember that they both come standard with SSD's. A ten-year-old PC with a Pentium 4 CPU and 1GB of ram would run almost as fast as your mac would, if it could support today's standards of SSD storage. SSD's will make any computer feel fast.
Make a wise decision, and do your research before buying a high-priced netbook to try and do intensive tasks like photo-editing or something like that. and if you're trying to buy an air to be fast and save money, you're an idiot. A $12-1500 MSi laptop will run circles around even the fastest $2600 dollar Apple. Apple makes a really nice product, but if you're trying to get performance for your money...you're looking at completely the wrong brand.