Novais a gem of a novel. If you can get past one huge faux pas, any sf buff with half a brain should find something to enjoy in this book. Nova is primarily a space opera. If you don’t like space opera, don’t worry, the book is more than just space opera. It is a thoughtful extrapolation of the future (well, except for the faux pas), as well as a philosophical mind- twister.
I just finished reading Connie Willis’s Doomsday Book. Let me just say that I am significantly less than whelmed. If there’s a bar here, about yay high, and it’s got “Whelmed” written on it in big block letters, this book is significantly under the bar. Now I understand why it is a popular book. It is conventional. Very few, if any, science fiction tropes are involved at all (aside from some cutesie names, such as “vids” for “movies”, all phone calls are videophone calls [although none of those are cellphone calls; the book was written in the painfully early nineties, so it gets a pass on that one], and time travel).