Blindsight is a great book and it's understandable why it's so popular. Consciousness feels like a sexy accessible and intelligent topic, and Blindsight is an intelligent and shocking first contact story even beyond that philosophical overindulgence.
With that out of the way, the second Firefall book feels like an easier read, and explores similar interesting (and honestly relevant) topics? Some of the passages and claims are weird for sure, but a lot less so than Blindsight.
Some folks might be put off by the faith/ religion debate and apology (the author himself mentions "faith-based hard SF"), but it should honestly be a non-issue at multiple levels. None of those arguments seem new, the author is great at framing his narrators as unreliable and biased, and it's honestly not really core to the story (unless you believe it to be so).
The entire posthuman premise, distributed and assisted intelligence, and the struggles of an "old-school" aging scientist to keep up also seem hyper-relevant in the current real-world context. Surprised it's not getting more attention these days.
The one legitimate complaint I can agree with is that the book might feel less alien and too accessible. The monks, the vampire, the non-baselines all feel relatable, which in turn feels dissonant in a post blindsight read. It's slower paced but feels like a shorter book. It does not force rereads.
Some of the above might be due to reading the books years apart, but overall Echopraxia was an interesting and satisfying read which should be more popular.