Their prices are actually pretty low in Houston, lower than I expected. E.g. Bellaire to Downtown $12-$17; Clear Lake to Downtown, $28-$37 estimate. Not that bad. I could see myself (and other people) using it, even for crosstown trips.
Edit: The base fare is $1.90 and $0.19/min, $1.48/mi - minimum $5.70. Compare to NYC where it's $3 base fare, $0.40/min and $2.15/mi with an $8 minimum. That's quite a difference.