True up to a point. Not limited to Iain M Banks, though: the Bridge does much the same.
The key thing to know is that Banks was a Scot, and sounded like it. (I met him quite a few times.) If you read the phonetic passages aloud in a cod-Scottish accent they are much easier and clearer, IMHO.
> 'Excession' had a lot of talk between Minds/Ships which was quite dense.
I can only say that I did not find that. It's widely rated as many readers' favourite Culture or IMB novel.
I though that, for instance, Vernor Vinge's A Fire Upon The Deep was harder work, and much as I love Vinge's work, I found Rainbows End unreadable and DNF.
> Also there is a lot of descriptions of hyper-advanced weaponry, drones, etc
Personally I lap that stuff up.
> even though I enjoy the books, it can be a bit much sometimes.
Interesting. For me the reverse is true. I find they make most other SF seem a bit dull and lifeless.
What I liked about Banks' sci-fi is that he generally avoided too much 'info dumping' that some authors suffer from. Like "He was a X'nar'kk from the Blagh'le system ..." for like 3 paragraphs before you get to some actual plot. The only time I saw that a bit was in the Algebraist - funnily enough - in the subplot with Luseferous (diamond teeth, enemy head punching bag). Of course the parts with the Dwellers made up for that ('I do hope you have enough people.').
I guess it comes down to whether all the detail is enjoyable or not. When it's a long description of how a Ship converts the majority of its mass into a swarm of weapon platforms or the rapid sequence of events in a battle between drones over the space of a millisecond then it can be good. If someone was not into that, I guess the extra detail is going to make it worse for them.
Excession IME is fine for people -if- they've read several other Culture novels first. Having it be somebody's first one tends to be ... suboptimal, at best.
Inversions is also weird in that it feels a bit empty ... -unless- you know to read it as a novel about SC agents, and then it's far more interesting.
The rest of the sci-fi ones seem reasonably grokkable, the non-sci-fi ones really depend on whether you get into the style or not, I think.
Also there is a lot of descriptions of hyper-advanced weaponry, drones, etc - even though I enjoy the books, it can be a bit much sometimes.
Of course, most are more readable in the original Marain :)