Funny enough I ended up having the same reaction to sand boas. Got a chance to handle a few at Repticon yesterday and realized I was very "meh" with them. Definitely didn't fall in love like I have with other species. Hognoses on the other hand I adored! I can only imagine how awesome and fun it is to watch Cosmo's personality blossom!
It certainly is fun watching him grow. He's hitting a little growth spurt right now and seems a bit more confident in himself. Although he's always thought he's a big, tough, scary monster.