I have the Cambridge unit, and used to have the Wadia (170, not 171). The remote on the older Wadia was limited in what it could control, I didn't like the (lack of) functionality. The Cambridge isn't a world-beater for functions, but it's better than the original Wadia.
The Cambridge is smaller, has more digital out options, will (perhaps awkwardly) fit the iPad, and has the better remote. I can't say if one is better sound-wise than the other, as I never had them side by side. But I like what the Cambridge did, and I liked what the Wadia did, sound-wise. Great recordings sound great, good ones sound good.
The Cambridge is sold street price for $300 new, and you may be able to find it cheaper. Personally, I think it's worth the ~$50 more than a used Wadia.