Lol at assuming your roommates will let you use their laptop. Sorry, but that's kind of unfair. What makes you think they'll be okay with that? I'm sure they'll have group projects, want to type a paper in the library, or have it for themselves to go.
I just graduated from college this past May and I have not once seen anyone loan their laptop out unless it was with a close friend or for a damn good reason--not because you have a desktop and want portability for that day.
I just graduated from college this past May and I have not once seen anyone loan their laptop out unless it was with a close friend or for a damn good reason--not because you have a desktop and want portability for that day.