I've spent a month, in two tranches, photographing in Nova Scotia. My views don't seem to coincide with others here.
First the area I enjoyed best photographically and otherwise is the coast south and west of Halifax. Particularly Prospect, Terence Bay, the Aspotogan peninsula, Mahone Bay, and the Blue Rocks/ Stonehurst area near Lunenburg. Within this I also like Peggy's Cove and the villages around, despite the fact that Peggy's is overrun. If you can get there at dawn ( I stayed in Peggy's only b&b with a balcony overlooking the harbour) you can get a lot done before the hordes arrive, go elsewhere for the day and get back at dusk when It quietens down. All told I think that rather more than half of the usable photographs I have from Nova Scotia emanate from this area, which is directly en route to Liverpool. The area round Shelburne, west of Liverpool is pretty good too.
I also quite like the area from Digby to Wolfville, which includes the Annapolis Valley and the Blomidon peninsula.
Now, Cape Breton. I'm not a huge fan i'm afraid and the only time I enjoyed it was travelling along the eastern side at peak fall colour in mid October, despite the fact that much of the accommodation and eaeries were closing up around us. Basically I just don't think there's enough opportunity to get close to the sea and the landscapes seem bland to me. Certainly if you've been to truly spectacular coastlines like western Scotland, Western Ireland, Oregon, I don't think you'll like Cape Breton as much unless you happen to be there in October. Clearly not everyone shares that view, so maybe taking a look on Flickr might make some sense, as i do before every tripto a new destination. I do like the Margaree valley and the Bras d'Or Lake round Baddeck much more.
Finally Halifax. Its a perfectly decent sort of place, but for me not photogenic or particularly characterful. It's close to a lot of nice places though.