A little over a year ago we started to look for a load balancing solution for both front end web application as well as the service layer of our applications. The first name which came to mind was F5 and within seconds the huge price tag came to mind, too. Trying to be economical, my next stop was Google, where I searched for other options. The typical providers surfaced: F5 again, Barracuda, Coyote Point, Radware, and Kemp. Our team requested demo units from a number of vendors, some sent them, and some essentially told us, "We do not want your business." Either our expect purchase size was too small, or they just did not send evaluation units (maybe cause their solution was too complex?).
While the demo evaluations were going on, I started to look for open source solutions. There were a number of resources like HAproxy and Pound that, if combined, could be a very strong solution. Of course I had no desire to become an expert in these resources, and then have to configure and manage them, so I dug deeper and found Loadbalancer.org and their enterprise solution, ClusterScale. The more I learned about the company the more I liked them. From combining open source solutions to offering the solution as a virtual machine within ESX, to the pricing, they seemed ideal. After some good evaluations--which were set up in a matter of minutes since it was a virtual machine--we moved forward with ClusterScale in our production environment.
Since then we have been very pleased with ClusterScale and their support. This company just "gets it." They understand that providing open source solutions is more than just charging a lot for it and calling that "support." They understand that support should be staffed with real engineers that can answer actual problems quickly. They understand it is better to help a customer do something the right way compared with the "cool way." I have dealt with many enterprise open source companies in the past, and this is one of the few that is doing it the right away.
If you are looking for a load balancing solution that is easy to work with, does what it should, and is supported by a great group of people, then I would recommend ClusterScale. If you are looking for a large name company with overpaid sales people and solutions that are too complex, then go with one of the other more "established" players.
