USTA league play is big in my area, but we also have a great local league. I play mixed doubles in that league, and the matches are much more interesting without the USTA restrictions.
We get a lot of husband and wife couples, so playing against a 4.5 man and 2.5 woman happens. The spread between players on the teams is pretty large as well. We've got 5.0 men on my team as well as 3.0 men.