I will say you've cheated a bit, Shem. Planescape is the coolest setting in the infinite multiverse, so it's almost not fair that you get to have access to all that coolness.
I think my favorite part about Planescape is that certain places can be nearly physical manifestations of certain emotions or ideas. It's very compelling to have tangible Hopelessness. Would Sigil be Cosmopolitanism? Eclecticism? Ordered Paradox? Regardless of how I'd describe it, it makes for a great setting.
The posts are a bit long -- I've only read the prologue and the first one with Clueless -- and the writing occasionally has a few technical errors that throw off my reading groove. But the actual cadence of the writing is usually pretty easy to read.
Clueless makes for an interesting character, in sort of the same way that the classic "assassin with amnesia" does. He knows a lot of things I have no idea about, and as he learns what he has forgotten, I get to watch and be dazzled. I like being dropped into the middle of a mystery, but there is a lot here to catch up on. Care to give me a quick update on how much you've written since then, and how close things are to being done? F'rinstance, as much as I love Piratecat's game, I got hooked early. I couldn't imagine working my way through the whole story from the beginning.