At about the mid point of the book and dear god this is some good writing. Makes most of the other stuff i've read seem like primary school fiction in comparison
Is there an obvious progression after this book or is it worth jumping to some standalone stuff for a bit of a break before coming back?
You have two choices - gird your loins and keep going, or take a break with something lighter to give your brain a rest. The books are linked with a thread of continuing the stories of characters and stories set in the same universe, but you might get through half a book of what seems like a separate story before you realise where the link is to the one before. The stories are more like a web rather than a linear progression, so they can feel standalone, but set in familiar places. Each book can seem like something new, but it's set in the same universe, and the amazing world building just continues again and again with new characters and links to what has come before.
I read them consecutively as they were published, so I did get breaks, but it may be easier to read them together as it holds the story and universe in your head. If I took breaks, I would probably intersperse the Revelation Space books with short story anthologies just to put a different, less dense style of reading in my head for a while. If you want to stick with Reynolds, try some of the more standalone of his books that are set at a different time, such as the two Prefect books, or Chasm City. While technically a standalone, it was the book published after Revelation Space, and pretty much takes place at the same time, but on Yellowstone, so you get that world built for you.
Wiki has a
list of his novels, and I would say they are all worth a read, but his weakest are the Poisidon's Children trilogy, and Terminal World, as they didn't particularly grab me, but everything else is worth a read.