I'm a player in neither; that said, the two main games:
The PCs woke up in cells in a mad wizard's lab, and had to effect a daring escape with nothing but the clothes on their back, during which we discover we all have the same birthmark in various places on our bodies. We had made it to a portal room and were under heavy attack, and just when things looked hopeless, NPCs showed up to save the day and help us escape, then gave us a quest. Along the way we rested in a tomb that was filled with basically baby Tyrannids from Warhammer and killed them all, acquiring a magic sword my Voidsoul Genasi Swordmage(Named Ezuri in a moment of uncreativity, but Ezuri, Renegade Leader is badass both as a card and from a fluff standpoint so who cares) now has. We reached the city of Nephtet-Ra like we were told to go to and petitioned the queen Neferiti to arrange us passage north, name dropping the NPCs like we were told. We're currently on a fetch quest for her to get a will from an ancient tomb full of puzzles and riddles. (Which have so far been of the solvable type, I got two of the three riddles for one door within like two seconds of thinking them over, thank gods) The DM is running 4E with 2E sensibilities.
The PCs had taken some downtime after finding the cure to a obscure supposedly extinct poison that had been used on one PC's father, killing a Beholder and uncovering a plot by the Winter Court. We were all summoned to Sigil by the party's bard to help him search for his father. After hunting out a succubus with information and my Paladin objecting like mad to the Bard signing a contract with her putting his soul at risk to try to get his father's soul released from the hells, we've been trying to dig up information on what the succubus was trying to get us to do that the bard's father had failed at, which has involved such exciting things as shopping trips, visits to the library and to the Planar equivalent of the DMV. I don't think any of us even has any idea what we're going to do at this point. >_>; (It kind of illustrates why Sigil is my least favorite part of Planescape, not that the planes outside of Sigil in 4E thrill me much. Planescape's awesome for me was always in the planes themselves. Sigil's also the kind of place my Paladin hates. Too bad I'm not playing Xybapi or Vel, who were both 3.5 chars, they'd be all over Sigil and probably care about what's going on more despite not knowing the Bard. Herp. Oh well, there's always going to be part of a campaign you and/or your PC don't care about. But yeah, we just got to Paragon and we've gone from being badass heroes to being loser Clueless who need a guide every time they need to do anything and can't even find their way around on their own. Sigil makes Prime PCs lame.)