Not only goes he look MUCH better this way, it also shows his growth as a character. He wanted to change his personality and his look but in the end does go back to his old personality but more mature. He keeps his new look, which is similar to what they did with Topanga in Boy Meets World. She used to be a very hippy-like person and it definitely showed with her appearance. However, as she got older she changed her appearance (like when she cut her hair) but in some ways stayed the same inside but also matured. Farkle has definitely shown character development like the other characters, ironic considering his father was completely forgotten after season 1 until graduation but is forgotten again. So his look not only shows him being more attractive but also maturing and learning to grow as a person while still being himself.