We did it in May of 2005, which is about as high as the water has been in decades, so bear that in mind and realize your experience will probably be different. We did it in IKs. Our group consisted of one experienced kayaker, one pretty newbie kayaker (me), one experienced rafter, and one newbie rafter. We also met a really cool guy at the put in named Mike who'd driven out from California to run it solo who joined us. Here are the things I think are worth pointing out.
The water in the creek was cold. Really cold. If you don't want freezing cold water nailing you in the crotch first thing in the morning, I'd suggest splash pants or some kind of neoprene. One of our crew ended up sitting on something to raise him up a bit, so that's also an option. The water is also pretty muddy, but the side streams were a lot clearer. We pumped water from the side streams.
There was one mandatory portage where it totally sieved out, but you can eddy out right above the boulders and it was an easy portage. There was a second spot where half of our crew portaged and half ran it. As I remember, it was basically a 3' or so drop, but that was about it (no lead in or run out). I don't remember any other rapids besides some small riffles.
The side hikes are awesome. Make sure you have time to do some. Lots of little slot canyons. Beware of flash floods. Seriously. It can be raining 50 miles away, blue skies where you're at, and flash the canyon you're standing in.
The hike out at crack in the wall is not really that bad. We did it all in one trip, and as I remember it took about 3 hours. I had the easiest time because I brought absolutely minimal gear. I'm not sure I even brought a tent. I definitely didn't bring a sleeping pad since I remember sleeping on my boat most nights. One of the other guys brought tons of stuff (finger nail clippers, ipod, a few beers for the first day, etc). Another guy brought a paco pad. All of us hiked all our stuff out in one trip, so it's a matter of what you're willing to live without during the trip to avoid hiking it out at the end. We all did Mountain House meals, and brought I think 4 bottles of tequila and packets of margarita mix for beverages. The heaviest thing is obviously the boat, so if you really are intending to bring a tandem kayak, you might want to think about how you're going to carry it (assuming you do the hike). We also had one guy who got a new backpack frame for the trip, and it ended up bending under the weight of the boat. Doing a short pre-trip hike with all your stuff might not be a bad idea to avoid running into problems like that.
The hike starts along a creek bed and is pretty easy hiking. It diverges from the creek and you start hiking up the dunes. This part is the worst since you're sliding back a bit with every step. Once you get to the cliff, there's a crack that's really easy to scramble up to the top where you can rope your gear up. From there you can see the sun glinting off the cars in the parking lot in the distance, and it's a pretty flat hike over sandstone to the parking lot.
Here are the pictures from our trip:
You can see pictures of the one rapid and the hike out, and also get an idea of what the rest of the trip is like. I guess I didn't take any pictures of the sieve.