If the 5400 had a digital input, I'd already have one.
The local Spearit Sound is a Cambridge Audio dealer. Over the years I have heard quite a few CA CDPs. A friend of mine has owned two of them. So far, none have been overly to my liking. From what I remember, the lower end ones are overly bright, and the upper models lack impact. To be fair, I have not heard the 840c. Likewise, I haven't auditioned any Cambridge gear in about 3 years now so perhaps I'm due.
For purposes of this discussion, I'm really only talking about units that are dedicated DACs, or have a digital input. I don't do much with physical media these days except for ripping it.