I'd try and listen to both; a lot of people rate the Cambridge around here, and I have the Marantz SA7001 KI Signature CD player which I really enjoy. Never heard the CA, but if the 7003 matches or improves on the detail, speed and resolution of the 7001, you won;t be disappointed.
I have found the Marantz needs careful matching though; forget lean sounding amps or speakers as it'll leave you wondering what the fuss is all about. It does do bass, but not if you're a metalhead or a party animal. Mine is partnered with Audioquest Copperhead cable (£60 or so) and it is a good mix.
If the new 7003 adds a bit more muscle to the bass, you could be on to a winner. Obvious other big benefit is the ability to play stereo SACD (well, it was to me as I have a few now) and moreso if you're a classical music fan given the availability on hi-res. CD performance of the 7001 is top notch. Amazing midrange and treble, so look for that to continue in the new line.
Although different, I auditioned an Audio Analogue Paganini CD player over the summer, which upsampled, and I was very impressed by that player. One little caveat to all that is the Paganini comes in at around £1000 or did, so you have twice the price over the 740C. Superb used buy though (should be around £350-£425 depending on condition and age for a more recent and mint model).