I love Sanderson and read everything he writes, and Elantris is my least favorite book and I haven't reread it since my first time. I'm still planning on rereading it before book 5, but it hasn't really been essential at all to Stormlight Archive. If someone, like the OP, gets bored with some fantasy ... I'd stick with the most interesting books. In fact, roll from Mistborn trilogy to the Wax/Wayne trilogy because those are fun. Save the Stormlight Archive and Elantris until you are completely sold on Sanderson, IMO.