I don't know where else you're interviewing, but 9 or 10 programs was the magic number last year to be assured a match (the "charting outcomes" sent out by the NRMP).
Regarding the program: Mostly private patients, residents rotate at LBJ across town to get hard-core indigent experience. Residents really seem happy. 1 going into Urogyn this year, 1 into family planning or laparoscopic, can't remember. Was told that most residents enter private practice. Gorgeous facility. Have heard from several applicants that an in-house AI would (have) been beneficial- there are > 20 students from UT-Houston alone applying!!
Regarding Houston: Big, hot, southern. Decently cheap housing- possible to own a condo/townhouse if you're single, house in the suburbs if you're partnered. Wonderful culture, entertainment, & shopping. Definitely a driving city, traffic can be a b!tch.