How long is this game generally? I've been playing it on and off all day and I'm just about to encounter Pharod I believe.
Also, somewhat tangentially, how are Obsidian's modern day CRPGs? I've been very interested in Tyranny.
Pretty much every game Obsidian's ever made is great. Tyranny has a really cool world filled with interesting characters and well written dialogue (not as good as Planescape, but still great). A lot of people hate the combat, but it's not that bad. It can get a bit repetitive but the hardest difficulty provides enough of a challenge that it still feels fun despite that. Well, until the last chapter where it turns into a complete cakewalk.
Aside from that, Fallout New Vegas and Alpha Protocol are both incredible games. Pillars of Eternity didn't particularly impress me since it was much too focused on the combat, which wasn't good enough to carry the game. There's also Dungeon Siege 3, which is a fun enough action RPG, but nothing particularly amazing.
Lovely, I'll definitely give Betrayer a look too. Other than Tides of Numenera is there anything else out there even remotely similar to Planescape in terms of tone, story, characters, etc?
Aside from what people already mentioned, there's also Arcanum: Of Steamworks and Magick Obscura, which has a very interesting world coupled with some great quests, although the actual writing itself isn't all that amazing.
I also can't say enough good things about Sunless Sea. Just like Planescape it has an incredibly weird/awesome setting coupled with some of the best writing out there, although it's not as character focused as Planescape and mostly focuses on individual self contained stories instead of having one big narrative. It's an amazing game though, and felt more like a worthy Planescape successor than pretty much anything else I've played.