Best time to go: right before dusk. The flows peak late in the day, and more water is always better.
The gauge- this is sometimes a little tough- last year the lower drainages (above the gauge but below the take-out) seemed to be running harder because of that late snow, so levels of 300 were good to go because the level on the run was somewhere between 110 and 250 (a guess). It got pretty big in there for a week or two last year, when the guage read something like 300-400. The year before, it seemed the online gauge was fairly accurate to the flow at the takeout (125-180cfs). So right now, you have to rely on the visual until we get a sense of what the runoff is doing this year..
Overall, it would be a good idea to jump in on the low side for a first run. You'll need to drive into the takeout and check the flows to see if it's enough to float. Doesn't take a whole lot- but high flows are pretty continuous and eddies get to be a little tighter. Medium flow are perfect cause the eddies are big and the rapids are filled in. You can walk scout the majority of the gorge in about an hour.
Maximum group size is about 4, IMO. If someone gets pinned below you, it can be easy to run into the back of them.
I've got a crew that is going to run it tomorrow night or Sunday night, and more than likely after work during the week. I'll post a report if it's running.