You paper "A catalog of stream processing optimizations" is great! It seems like a classic in stream processing for me :)

Generally I agree with this comment. Very few niche applications require stream processing and all struggle that had been into research to enable some of the ACID properties for stream processing.

While at it, would you know how kdb+ (mostly used in finance) work? It -- together with q -- seems to achieve very low latency for real time systems.