It took our friend Bill Wright five hours and it took us about five and a half hours. Bill is really fit and fast and we're not. The reason there's not much difference is that it's easy to get lost the first time you go. A friend who has done the route many times says he can do the approach in about two hours if he really goes for it, but he failed to get to the climb at all the first three times he went up there. The keys are to stay to the right of the drainage coming down from Alpine Lake and then, from Alpine Lake angle up and right (west and north). When you get to the Conness Plateau, shoot straight down and over to the notch and drop down the gully.
The climb is pretty obvious. It is the most spectacular if you keep to the right with views over across the south face and dramatic exposure. No matter what, though, you'll eventually end up on the knife-edge ridge that drops away on both sides for hundreds of feet. At several points the easiest route is actually out over the abyss. To me, this blows Matthes Crest away. Some people say they prefer the North Ridge of Conness, but I can't speak to that yet, since I haven't done it.
The climbing is enjoyable, clean and generally quite easy even for a 5.6. It's more of a scramble most of the way and probably more enjoyable in sneakers than in climbing shoes. Most parties will want to be unroped for significant portions or all of it.
The descent is obvious and similarly beautiful. A short ways below the summit, at the Conness Plateau, you rejoin the way you came up and follow that back down (if you went the right way).