I use to run the AD2K+, in fact ran it for 3 years??? can't remember, something like that. Anyhow, it's a nice unit, but here is one other thing to consider. When I spoke to Benchmark about an issue I was having (Low power LED would come on too soon), the guy mentioned to me that the reason they stopped making the AD2K+ was because they couldn't get some of the parts anymore (sound familiar?). The unit is a bit old in the tooth, but it's built like a tank, so it should last for years. However, if something does go wrong with it, there are chances you might not be able to get it fixed if it happens to be one of the parts Benchmark can no longer get. This obviously must also be taken into consideration.
Wayne