Thanks for all the advice on the two kits. I finally decided on the Stoptech for under my tree (or at least a picture of it, the kit is backordered right now, possibly a testament to their popularity). Ultimately, I think lower cost of ownership (the salesperson said I could expect the Alcon kit to have ~2x lifetime costs of the Stoptech), better parts availability, lingering concerns about StaSis, and higher favor from R32 owners for the Stoptech kit won me over. Plus, it is nice to support a vendor that supports BMW racing, and nice to have an American company to deal with if there are issues rather than American distributors.
As an aside, while researching Alcon a bit more, I found some of their racing brake parts in one shop -- how about $3500 -- for one caliper. Really puts in perspective what we are paying for these BBKs, and the difference between these and true race parts.
2011 Jerez Black/Fox Red E90 M3 DCT, ZCP, ZCV, ZCW, ZP2, BMW Apps
2015 Golf R