I'm not sure she pulled them together that well though - though I do think it's worth reading purely for the fact she rather unexpectedly uses the word cunt!
The trouble with the Niccolo books come, I feel, because she was - she freely admitted - at war with some of her readers by half way through the series. Speculation was absolutely rife in the fan world - Marzipan & Kisses, Whispering Gallery and the online forums - and she was constantly trying to stay ahead of quite a baying pack. She also tied herself to the life & times of Anselme Adorne which made for fascinating journeys and informative stuff about C15th mercantile life across the world, but really far too long a set of books. Who actually cares about stockfish? The salt trade is fascinating, but by the time someone got to dyeing their pubic hair black in Caprice & Rondo I was losing the will to live. I've read Gemini just the once - rather as people say about reading Checkmate - got my copy, inhaled it, thought that the ending was rubbish because I didn't believe in the Big Bad and the (terrible) motive, and that was that. Always back to Lymond, not back to N since then. I did pick up NR last year, planning to reread and couldn't get past the bath and the hennin, whereas Lymond I just sink back into.
I actually disliked the way she joins the books - the epilogue of Gemini is, for me, toe curling. I am part of a group of people who all got together because we read the books and saw each other's names coming up in Whispering Gallery and all lived near enough to each other to start having get-togethers, and we all feel she could have made them a totally stand alone series; there didn't need to be the links and I, personally, would have been happier without. It's nice to go "ooh look" but there's something about the linking and the mysticism in N - the weird bit in the Tyrol for example with the divining - that just doesn't work for me whereas somehow the Dame de Doubtance is so batshit and so baroque in Lymond that it has far more of a place. Perhaps it's to do with the fact that at the start, N is so grounded, the world is so much more human with the dyeing works, trade etc etc that I wasn't expecting it to have a place and I didn't enjoy it when it did.
I've also read King Hereafter, which I find tough going, and all the Johnson Johnson books, which are just horribly dated now, I think.
Summing up my personal feelings - she is at the height of her abilities as an historical novelist with impeccable research in the N series and King Hereafter, but she is at the absolute peak of her romantic historical novelist writing in the last four books of Lymond. "Oh mill, what hast though ground" indeed.