One thing I personally love is the straw - it's a flexible silicone so it's not the kind of straw you worry about your little one totally stabbing themselves with (but do note, it's recommended for 12 months and up). It's also valve-free, which is safer for dental health, speech development, and hygiene.
I was a bit intimidated by all the parts, but a quick review of the instructions helped me put it together lickity split (which is the only way when you have a toddler hanging onto you begging to have his new toy, errr, cup!