Yep, I'm fermenting in a keg with a spunding valve acting as the airlock.
My current favorite fermentation schedule is to pitch at 43 F, let rise to 48 F over the first day or two, and hold it there until I am about 8 gravity points above my attenuation limit. At that point, I raise the pressure on the spunding valve to 10ish psi to let the beer mostly carbonate. Once I'm 4 gravity points above the attenuation limit, I start lowering the temperature back down to 43 F over the course of about 2 days. This slows down the fermentation and also encourages the majority of the yeast to drop out of suspension. Once I'm 1 or 2 gravity points above the expected FG, I do a closed rack to my purged lagering keg and fill it completely. I attach a spunding valve set at 12 psi, and give the beer another 4-5 days at 43 F before starting to lower it to 37 F by 1 degree F per day. It sits at 37 F another 2 weeks or so, by which point it's crystal clear and ready to serve.
I usually have a bit of sulfur when I rack to the lagering keg, but after the 2 weeks at 37 F it's gone.
I'm using WLP835 with a pitching rate of about 20 million cells per ml for a 1.050 beer. I aerate (after pitching) continuously for 3 hours using an aquarium pump with a 2 micron stone and inline HEPA filter.
The whole point of this schedule is to make it easy on myself so I don't have to worry about catching the beer with exactly the right amount of sugar left, and also (and perhaps more importantly) to minimize the amount of yeast I carry over into the lagering keg. I am really only looking for the yeast to scavenge any oxygen that got picked up, provide the last little bit of carbonation, and eliminate any VDKs that still might remain.
WLP835 has been by far the easiest and best lager yeast strain I've ever worked with. It does exactly what I want and handles the above schedule beautifully. Why White Labs doesn't make it a year round strain is beyond me, because it's the best lager yeast they make.
