Yup. Higher levels are higher rewards. Unfortunately rental prices spike just before season end so watch out for that. Also those daily rewards do add up (yesterday got a Legendary and pack which had a gold rare and summoner). Just remember : having enough CP to battle in a league doesn't mean you will get wins for your daily quest (Gold II is a bear for me) and remember if you can battle to a league the guild will try to get you power for the maximum reward...if you ask :)