Don't judge a book by it's cover.... while the outside of this location may not look great (shoved in the middle of a strip mall), it does have it's positives.
Except for the 6-8pm after work rush, this gym is never packed... which means you will always be able to use the equipment you'd like instead of waiting 20 minutes to get a few sets in. The gym has begun a large expansion, so it will be able to compete with its newer and larger sister location on Scottsdale/McDowell. It's location is good and close to ASU, and there's not ever traffic to get there, at any time of day.
The staff is nice and helpful, and care about your success. It maintains a clean atmosphere, for the most part. I have never had a bad experience here, and I go 4 to 5 days a week.
All in all, I think this is a good fitness gym, and will be even better once the expansion is completed.