Avantages
Technical people are looked upon favorably. Lots of opportunity to advance skillset on the job. You can actually reach upper level people (CEO, chairman, etc). There is indeed free soda, coffee, and tea. It seems that leveling up within a position is quite consistent and regular (e.g. support 1 -> support 2).
Inconvénients
Gym is composed of solely of machines and dumbbells (no barbells for people who want to lift weights). The "cafe" mentioned is non-existent as far as I can tell. Free snacks is limited to apples and bananas. There is no official carpool program, although they list this as a perk (in fact, from what I observed there is no employee carpool, just friends who carpool). Rackspace University is geared towards IT and Management/Business, with other classes taking a backseat or not being held. On-site health services means free health screenings every so often. Career progression can be slow if you want to move up positions (e.g. support -> network).