What size laptop to get: 13 vs 17 inches?

Hello guys, gonna keep it brief but descriptive.

My first idea was that I needed a new computer. I currently go to college/uni and write notes in lectures and type them up at home on my old desktop. The desktop is getting old so I require replacement.

My first problem was whether to get a desktop + laptop combination or just a laptop. I decided on just the laptop as it will be easier to maintain and transfer files and generally easier to use than two separate computers.

I wanted a somewhat portable machine so I can bring it to uni and type notes, but also powerful enough for heavy duty works like Photoshop, games, other specialist software my degree requires. One laptop came to mind: Clevo W230ST. Also sold as Metabox and Sager and Horize. It it 2kg and has a powerful internal hardware.

Then I had another way. Just get a larger laptop 17 inches, and just take notes like before, without bringing a laptop to uni. The one Im looking at here is Clevo W370ST. Just to be clear here, hardware wise both are identical, same CPU/GPU/same res screen/made by same company/same RAM etc. Only difference is that 17 inch W370ST is larger and heavier (larger screen is not bad), it allows more hard drives to be added later on, and has a DVD RW drive. It also has eSATA port but I dont need that.

Lastly, price for the smaller 13 inch W230ST, say its just over $1000 dollars. The bigger 17 inch costs a lot more, about $1350.

Just wondering which of these two is best for my uses? Thanks