As a Houstonian, I can say without exaggeration that the Quilt Festival here is the biggest, most amazing quilting event anywhere. You can buy anything from special shoes to jewelry to antiques to lace, beads, machines, tools, oh my--- one booth sells over 1000 different scissors, tweezers, and other assorted metal thingies!
Take classes if you can-- everybody who is anybody in quilting, doll and toy making, wearable art, dying, and anything you can do with fabrics and thread teaches at Houston. Get autographs!!
Stay in the suburbs and take the Meteo shuttle bus downtown-/ hotels are cheaper and neighborhoods are safe. Room with friends and make it a slumber party. Rent a car (cheap) to get to restaurants in the 'burbs (stay off our freeways. They're dreadful!) Eat Tex-Mex! We also have amazing seafood, Chinese, Indian, and Cajun cuisine. (Which is why we are America's fattest city 5 years in a row!) Wear thin-ish clothes that other areas save for spring or summer and bring a sweater-- October and November are usually warm (often rainy) but every building runs their AC full blast and you'll get cold.
DO come. The show is amazing and Houston can be a lot of fun.