Did one of those "Best Hard Sci Fi Novels Of All Time" searches then bought the first three I had not read.... started the first one a couple of night ago...
it's called "Revelation Space" and I'm about 20% into it... it's ok, I'm not infatuated with it. Hopefully it gets better.
About hard sci-fi vs the others... I very much favor hard sci-fi fiction to the soft sci-fi.. in other words, more science focused than socio or politically themed.
Next up "The Three-body Problem".... hard sci-fi by a Chinese Author that according to many hard sci-fi fans is remarkable.
I believe, without checking, "Foundation" is considered the top Sci-Fi novel ever? I have never gotten to the 2nd of the trilogy yet... one of those I could kick myself in the ass things.