Bytecoin is a scam, whereas Monero is at least pretending to be a well-behaved open-source project. Also, there was a ton of innovations since the fork.
Apparently they've been working on forking out the overdistributed initial Bytecoins. My only concern with Bytecoin atm is they've apparently patented their approach, where that would lead Monero is uncertain to me. I was going to try and reimplement Bytecoin (in another language so I could learn more about how Bytecoin works) but I couldnt get an answer from someone from their group as to what the heck it means that they're patenting it.