Difficult decision if your main interest is in rendering, as nothing has changed there that I can see, same issues, same workarounds.
Probably the most usefull addition is the right click option of "Select All Similar". Allows you to select all walls (that are similar) and edit them all at once.
The Surfaces tool is handy for making sloping floors such as wheelchair access ramps. Theoretically it is supposed to allow you to also put other slope sections into a roof or ceiling, with an Intersect tool to 'join' them but mine, and presumably everyone else's, is locked to the ground level so useless except for floors. The roof can now be exploded into sections.
There are 2 solar panels for the roof but no solar hot water system with external tank attached (such as we have everywhere in Australia).
The 'automatic' quoining and shutters tools may be of interest and a few new accessories of various sorts.
There is a area calculator that will just drop the name of the room and its area into the centre of the room, (also perimeter and volume - ideal for aircon calculations), but if printing is not your big thing, then that will be of little interest, as will the Worksheets view.
Backward steps, from my point of view, have been made in the interface - the tool icons are far too big and because the Help toolbar cannot be converted from a Tab to Normal, you are stuck with a tab view taking up even more space. I know you use dual screens, so the loss of screen space that has occurred may not worry you but it is certainly significant on a laptop. The Tree style for selecting elements also means you cannot 'page' through them to see what they look like, you have to click on each individually. The little animated tutorials in help are nice for new ones but of little use to you. The Help Search/Index options in the Help are not there 99% of the time so help is very frustrating.
In summary: Some of the new tools and accessories may be of use and some of the additional right click options make things quicker, but in rendering nothing appears to have changed.