Not a comprehensive review as I've only been once, and from a purely (wildlife) photography perspective:
Snettisham
Well worth doing for the 'wader spectacular', when high tide pushes the birds off the mudflats.
RSPB timetable for 2014-15.
The good news is that September has a decent number of occurrences during daylight. When I went I had to start the walk from the car-park in the pitch black, yet there was a decent crowd building. After the birds have taken off, a lot of them congregate next to RSPB's lagoon; I believe this is where a lot of the
'Snettisham flock' photos are actually taken from (rather than the mudflats themselves, which are too far away). Unfortunately the winter storm trashed the public hide and I don't know the status of repair.
Titchwell
Another big reserve. The west side path to the beach offers a chance to get Bearded Tits (a decent length of reeds that edge up right to the path). The vantage points for the lagoons suffer from the common problem of being far too high, but the freedom to walk alongside does mean there is some opportunity to find decent compositions. The beach offers a chance to get covered in wet sand for low-angle wader photos.
Salthouse to Blakeney Point
A long area where salt marshes meet the beach. Runs from Salthouse in the east to the remote Blakeney Point in the west. Potential for success with waders, flocks of geese or marsh harriers. (disclaimer: the big winter storm had a large effect of the local geography. I don't know how it has changed and recovered since I was there)
Cley Marshes sits in the middle is a well-known nature reserve. You're meant to buy a ticket to enter the formal Cley reserve area and hides. I didn't bother with that* and instead worked the edge where salt marsh met the shingle. Keep an eye out for marsh harriers doing close flybys, especially when you're using one of the paths than leads from the beach to the coastal road.
* I made my financial contribution by being a patron of the cafe and bookshop.
The long hike out to Blakeney Point is no trivial undertaking! Potential to stalk waders and what not in the process. The tip is a seal and tern breeding area, check it's not the season when it's partially closed off (see my thread today for what not to do. Think it's all open by Sept).
Flickr Plug
I've still not properly finished going through my photos from the trip, but the stuff I have uploaded to Flickr:
https://www.flickr.com/photos/myphotograph/sets/72157637064953764/