I went through similar decision for my son. I decided on a no anual fee cash back card because because it will take too long for him to build up 25K points or mile to cash in on a reward. I have the following rule when deciding on a credit card:

1. Never keep a balance. If you can not pay it back, don't charge. Hence the low activity on my son's card.
2. Don't pay anual fees unless if you can at least 10x the benefit each year. If I can get $1000.00 benfit each year in goods and services from the points earned (above the benefits from a no fee card), then I am willing to pay $100.00 anual fee.
3. Make sure you are rewarded at least once year. My son's card give him cash back at the end year each year. He is one happy young man on that day.
4. Once you have an estimate of yearly spending, then you can decide on the type of reward you want. If you charge less than $25K, then it might be best to get a cash back card.

Nancy