Windows Mobile Power User recommends the L735 as an update for the 920:
"The more I used the Nokia Lumia 735 the more I liked it. After using increasingly large handsets over the years, it was a relief to use a thin and light handset for a change. Battery life impressed me, as did the camera, as long as you spent time focussing, and the ?unibody? design is outstanding. Surprisingly I would be happy to use this inexpensive handset as my daily driver, and would even go so far as to recommend it to 920 upgraders looking for a cheap handset in the spirit of their old device." (
Review: Nokia Lumia 735 (video))
The L735 is my first Windows Phone, and I love it. It takes superb photos, audio recording is good (I use Mini Recorder Free), is very comfortable to hold, has expandable storage and a removeable battery, not to mention wireless charging. It's never randomly rebooted or frozen, and I don't get any prolonged 'resuming...' messages. Fabulous phone for the price.
EDIT:
Also, the 735 has Denim and here in the UK Cortana is available and works a treat.