They are also in Chicago Equinix, however they may have differing services available in that location; for example remote-hands, power switching, etc. Note that they use Level(3) literature as their "our network" information, however they also use some Cogent transit -- which is not necessarily a bad thing!
Colo4dallas (http://www.colo4dallas.com) is a great place to do business. Not only it is staffed 24/7 on-site, but I've never seen people who are interested in growing your business like them. Very easy to work with, very reasonable pricing, great facility. They are also cash flow positive (very important if you want to be in business in the next 5 years).
If you haven't seen them, I would recommend to check them out.