I've never played an Ashdown amp before but they've always been in the back of my mind because of bassists like John Entwistle, Adam Clayton, James Lomenzo and more recently John Myung using them.
From what I've heard from YouTube demos and live recordings is that Ashdown amps have treble and top end. That's all I can really say about them. I've never really been convinced on the quality of the low-end in said demos, videos and recordings. I happen to like Entwistle's absurdly overdriven/chorus'ed tone on the Royal Albert Hall DVD, but listening to the U2 Chicago 2005 DVD on the other hand all I could hear from Adam Clayton was a lot of clank, not a lot of low end (Then again it could be because of the pick).
That being said I did find a demo that convinced me somewhat of Ashdown's low end quality, and I think I was won over more by the Retroglide head (Especially at the 1:45 mark) and it's one I wouldn't mind buying second-hand.
Am I missing something or would I have to try one out to "get it"?
I've owned a range of Ashdown and never found them shy in the low end. If anything they tend to have a natural warm tone ie. slightly heavier in the low end than the top end. Currently using an ABM500 and have to dime the treble to get enough. Low end though is a different story..plenty at the get go. The Ox had his own tone, which was very trebly and processed in the final range of gear he used