Just wanted to put a not up about these guys, who I've been talking to very recently.
After trying load abalncing Exchange CAS roles using MS NLB, we discovered severe performance issues - and it looked like a hardware loadbalancer would be the way to go.
However after a bit of hunting I found these guys, who gave me a 30 day trial of their Loadbalancer Virtual Appliance - which is pretty damn awesome, and I thoroughly recommend!
However the impressive bit was the licencing situation. I was a bit confused by some of the terms, and unsure which version to buy. So gave them a ring, and Richard Halcrow, one of their sales guys ran me through all the options. And explained that the difference is only licence code locked features (so upgrade is possible at any time), and that the upgrade cost is the difference between the individual versions prices.
I was gobsmacked, having being bled for cash for even minor version changes before!
So in the end I got a Pair of Virtual appliance loadbalancers for £1500...
All in all, if you're looking for loadbalancing (either for resiliency or performance) then I'd recommend giving them a look. #
Load Balancer .org - Virtual Appliance
While we are on the subject.... If anyone wants a demo of KEMP's Virtual LoadMaster they can message me too!
We use lb.org extensively at Smoothwall - helps that their head office is very close to our dev office. Always found them to be excellent, and able to micturate from some vertical distance over a number of competitors, including some significantly more expensive...