If I could do my degree over again, I would take summer classes every semester. I only did it one year; I took a psychology course again (that I had failed) and got over 80%, and two of my Shakespeare requirements and also did really well. They were my most favourite classes of my entire 4 years. Because I was with the same people every day for a longer time, I actually got to know people and made connections. I also wasn't able to procrastinate so I had more focus.

Good luck in your summer courses!