I loved The Algabraist and absolutely adored Feersum Endjinn. IMB hits me where my soul lives.
I do feel that TA takes a bit to get going - a somewhat leisurely set up, the first 50-100 pages move along with the Banksian verve of some of his other novels - but once it's up to speed I found TA gripping...in fact, the concluding chapters are very much page turners for me. I think I stayed up til 3am to finish it. I also suspect that the Dwellers are a lot less "human" than they appear at first glance. Chances are a realistic gas giant alien would be incomprehensible to us and we to them...but that would make for a much shorter (and very different) story.
I know IMB is famously allergic to sequels, series and trilogies, but I would love to see him revisit this universe in a future book. I know he's said he will not (such a tease, admitting the TA reads like the first installment of a trilogy), but I wish he would write another. And I'd like another novel set in the Transition universe while he's at it too, please. It will probably never happen, as Banksy is too in love with his Culture universe to spend much time outside it.
Being a Yank, I'm completely innocent of Blake's Seven. It was one of those things I always intended to catch up with and never did.
I too adored Feersum Endjinn! In fact I wish he would write a sequel to that, I want to see more of Bascule. But no, I think Banks is wise not to write sequels. His endings are all so brilliant, the best is to just end it there, any follow-ups will ruin that long lasting after taste.