Cartel is fine. I go here a lot because I live right next door.
Cons - The service is hit-or-miss. They have a small staff and are pretty busy so it's usually about a ten minute wait from entrance to exit if you're getting coffee to go. The line takes a few minutes and the drink takes a few minutes.
Pros - The coffee really is good. The people that make the drinks are skilled and everything comes out delicious. The atmosphere is artsy, funky and fun.
Prices are okay. About the same as Starbucks and more expensive than Xtreme Bean, but a better product for sure.
I think Cartel has cultivated a loyal following of people that come for the coffee. Convenience is probably also a factor because of the sweet location. If you really care about high-quality coffee, I'd say it's worth the effort. If you're just in the mood for an iced chai, you'd be better off going to wherever's closest to you.