Jasper on his SmartCat Multi-Level Climber, which he loves. All of the cats like the SmartCat Ultimate Scratching Post, which I love, because it has helped in furniture destruction prevention. I prefer the sisal matting to carpet, because it doesn't get stuck in their claws, doesn't leave bits of fiber all over the place, and it is more durable, which means there are no loose strings hanging off for Emi to eat.
My only complaints are that the shelves on the climber are not made of the same material, and Jasper has nearly destroyed them in a couple of months, and that it doesn't sit flush against our door, so it knocks around a bit. The latter may just be an issue with our door, however. Overall, I am very happy with both purchases, and will likely purchase another scratcher, and possibly another climber to satisfy the savage beasts that roam my house.