If anything technically an upgrade due to higher FPS, CPI, and smaller casing. From a purely technical Hirarchy, S3988 would stand on top, then A9800 and then PMW3310H.
S3988/S3989 and PMW3310 have the same Variance given same circumstances, which is worse than the previous Generations. PMW3310H(and S3988) are also not really raw, close but not what you can consider raw, especially with Zowie´s FW.
I am talking MCU and Syncing.
Still a saving that doesnt reach the Consumer.
There is no need for testing considering specs, the difference between 3310 and 3988/3989 is basically Case, FPS and max multiplier. PMW3310 is more common due to price and case, you can just reuse old PCB´s which you have prior used for A3090/3080/etc., which comes pretty handy for corner cutters like Zowie.