Thanks a lot! i am leaning almost completely towards the 15" macbook pro, but i would like to know if i were to rip movies/ unzip/zip large files or convert file formats, does the 15" macbook pro does it significantly faster than the 13" pro or air? and if i were to compare 13" pro and air, will the air perform these actions much slower than the 13" air because it is less powerful?
Thank you very much for the help!
No problem!
And yes, as I said before, due to the difference in processor cores, the 15" will zip ahead of the 13" in a lot of basic, and complex tasks (such as the ones you mention).
Just for you to compare, here's benchmark scores (considering you purchased 2.3GHz 15", or 2.5GHz 13") to help you understand the difference here:
http://puu.sh/GjLV
http://puu.sh/GjMn
I'm sure you'll benefit, especially in the years to come, by having an extra two cores to help you do your work.
As far as the air goes, the processor won't be faster, necessarily, but simply because of the SSD, your applications will open quicker, respond faster, and flow more consistently. You should ask yourself what you need most: a faster processor for heavy workloads, or a faster drive for an overall smoother, more responsive experience.
To compare to the 13" MBP, here's the benchmark score for a MBA with an i5:
http://puu.sh/GjOQ
Overall, any of these computers will suit you well: whether the 15" with more power appeals to you, or the speed of an SSD in a MBA. Good luck with your purchase decision! If you have any more questions, post away!
Benchmarks (so you can compare the more in-depth scores): http://browser.primatelabs.com/mac-benchmarks