Well, it's not exactly typical, but then again, a 90 point brew isn't typical, either. You could have pitched a more vigorous and greedy yeast, or doubled the pitch, or optimized the temp, and maybe have finished all major fermentation in 4 or 5 days but you might have had a big blowout, too. Sometimes a little slower attack by the yeast isn't a bad thing. I don't think you should be worried at this point. It will probably settle down in a few days. Are you by chance taking hydrometer readings every couple of days?
I used to be sort of noid about taking samples. But what I do now, minimizes impact on the batch. I use the plastic storage tubes that are often supplied with the hydrometer, for a test tube. They don't require much beer to float the hydrometer. Yeah, they are pretty cramped but if you carefully tilt the tube this way and that and try to catch the reading when it isn't touching the side, and average the reading over a few minutes, you can get a pretty accurate reading. To prevent air being sucked into the fermenter, I open the spigot slowly and watch the level of the alcohol (I use everclear in my airlock, as well as for other things) in the atmosphere side of the airlock and I stop the sample pour before a bubble can get sucked down and across to the fermenter side of the airlock. I let fermentation gas build back up and push another bubble to the atmosphere side and then crack the spigot again. Repeat as needed to fill the storage tube up about 60% full. Then I try the hydrometer. So I have my sample, a small one that I won't even miss. Also I did not open the fermenter or even backflow the airlock while dispensing it to the testing tube. I have been doing this daily with the current batch, comparing results to my brand new bluetooth Tilt hydrometer floating inside the fermenter. I keep another tube of clear water next to the fermenter to correct my regular hydrometer reading.
How long did it take to start working, and how long to start burbling constantly? If it wasn't working hard until 24 hours after pitching, I would expect a two or three week fermentation. If it was practically boiling 6 hours after the pitch, I would expect to see it die down in 7 to 10 days.
Where is your temp, within the ideal fermentation temperature range for that yeast? At this point maybe you would want to hurry it along, and get it up near the upper end of the ideal range.
I haven't looked at the spec sheet for that yeast but my gut feeling is that you did well, pitching two packs rather than one. Keep in mind I have only been making beer for a couple of years so I am not Mr Knowledge and I might be missing something here.
