409 is maybe the best section in the upper level. The 400's are actually on the second level of the arena so don't get discouraged when you see these seats on Stubhub or ticketmaster.
Have sat here for two rockets games, once in row 3 and another time in row 10.

There are only 13 rows in this section, so it doesn't get very steep.
Not close to the action on the court, but you won't miss a play. Go Rockets!