We have been using an enterprise backup solution from www.thinkingsafe.com for about 3 or 4 years now. Its a solid appliance and I would recommend it to anyone looking at enterprise level backup for server (incl. exchange) or clients machines.
I also got a mention on the website:
Red Chilli head of IT Simon Page told silicon.com: “This is a solid piece of software that gives us peace of mind that our data is secure. We store a lot of confidential financial information and safe, secure back up systems are critical to our business. It would have a big impact if our systems went down and we couldn’t access our data.”