I'm in a similar boat. I've only done 3x3 and GIANT CUBES (7,9,13,15) until recently. I am finding 2x2 Ortega kinda fun and i would recommend it if you want a small lag set for a very fast event. 4x4 & 5x5 Are also fun because you get introduced to new concepts, centers and edge pairing but the solves are much longer (I like that aspect). BLD is great if you want to cube but also want a total 180 on Your cubing experience.