Which Size?

How did you decide between the 13 and the 15??? A lot of extra $$ for the 15. Any difference in the screens other than size?

 

Graphics card and CPU speed. Probably better sound on the 15 from the external speakers.

15" has a higher resolution (obviously).

 

Really depends on what you are going to be using it for.

 

people go mostly for 15' due to better upgradability options not really the screen, if 13' model came with better gpu and better cpu then most people will be buying 13 inch

 

I have the 13" and I am having no problems with the screen size/resolution whatsoever! It all depends on what you want to accomplish with your laptop.

 

The 13" MBP is a very nice machine, but the 15" is noticeably nicer
Depends mainly on what you plan to use it for, of course.

 

I chose the 13" because I will NEVER buy a bigger laptop anymore. Best size/portability compromise IMHO if you are actually going to carry it around/travel with it. I've taken pretty much the Goldilocks approach to laptops, had a 17" (fast, but too big heavy), 12" laptop (good size, but slow), 10" netbook (too small for prolonged use), 15" (fairly fast, but still kinda bulky to travel with), 13" (just right, not too big, not too slow). Also, my measure of "slow" is not being able to play back 1080p HD video.

As far as MBPs go...screen size, CPU and GPU are the main deciding factors. CPU is kind of a wash IMHO since most people don't exploit the full potential unless you game or use CPU intensive programs...so that leaves screen size and GPU. Again, the GPU isn't fully utilized unless you game or do 3D modeling. So now we are down to screen size as the deciding factor unless you have a specific need for faster CPU/GPU

 

What can you upgrade in the 15" that you can't in the 13"?

 

I think he meant you can buy/order it with better/faster options. As you imply, the "user upgradeable" parts on both the 15" and 13" are the same.