Sadly it's been years since Microsoft released any successors to phones in the 900 series aside from the AT&T exclusive 950. Even the 4 year old Lumia 920 as well as the 928 are still superior to Microsoft's newest phones in the 500-800 series. I used to have a 928 but I couldn't wait any longer for Microsoft to release a new phone so I had no choice but to temporarily upgrade to a Galaxy S6, hoping that once my contract is up, there'll be a new Windows Phone for me to return to.
To answer your question though, the 928 is far superior to the 735 across the board except for the CPU and front camera. The 928 has a dual-core CPU while the 735 has a quad-core, albeit at a lower clock speed. The 928 excels in all other areas though despite being significantly older than the 735. The 928 has the better camera, flash, glance, dedicated camera button, hardware buttons (preference based) and so on. The 735 does have the advantage of a microSD card though and replaceable battery. That doesn't mean the 735 is a bad phone though. It's just switching to it from the 928 is really considered more of a downgrade. I know someone that switched to the 735 from the Lumia Icon and that is quite the downgrade indeed, but so far the 735 has been "usable".