My experience with Ubiquiti has only been positive. Granted the largest deployment I have made with their AP's is from 2010 (60+ Aps + Cisco backend + PacketFence). A lot could have changed especially with vendor lock-in that the article points out. At my current work place we use 10 AP's with a mix of Cisco and HP gear for Core and Access layers and everything works ok.
I find that APs are good but their switching & routing products are lackluster. I expect a lot more features considering the price.