I work for Xirrus as a Principal Technologist. I will answer the original questions from Impgr7 first:
Product - we aggregate 4,8,12, 16 or 24 abg+n radios into a single platform with an onboard Gigabit switch, integrated WLAN controller, 24x7 dedicated threat sensor, and spectrum analyzer. How this translates to our customers is that they are able to get more capacity with 75% less devices, cable runs, switch ports, and installation time.
I have been through all the CWNP certifications (Wireless#, CWNA, CWSP, CWAP, and CWNE) and could go into many more technical and architectural benefits, but at a high level, the Xirrus solution allows you to do more with less. Feel free to email me at firstname.lastname@example.org if you have specific questions.
Quality - The MTBF of this product is 100,000 hours. Server grade power supply. PowerPC processor in every unit. High-gain directional antenna system with RF absorbing foam, reflector ring, EM absorbing paint to provide 4 times the range of anything else on the market. We were recently selected to provide the WiFi for INTEROP 2009 (LV and NY), which is our fourth time being selected.
Service - in the US, we have a direct sales business model. We provide no charge professional services to include site surveys, installation assistance, training, and post installation coverage validation.
Warranty - We do no charge live/active site surveys, which allow us to provide the industry's only 100% guarantee. If additional product is needed after the purchase, it is no-charge to the customer. There is no "bait and switch". Also, our 802.11n platform comes with a 5 year hardware warranty (most other vendors are 90 day, with some offering 1 year).
This is fairly long, so I will address GStefanick's comments in a separate post.