I used a similar trick when evaluating mice and monitors for gaming, but only had 60fps, but used some tricks (seperate lcd based display displaying microsecond

I used a similar trick when evaluating mice and monitors for gaming, but only had 60fps, but used some tricks (seperate lcd based display displaying microsecond timer in frame, some other timing hacks) to discover my trusty old crt outpreformed even the best flat panel in latency and black level. Still use it for gaming, and scrounging for another for when it finally goes. Other discoveries were being able to vary the ps2 keyboard polling rate (although the correct way seems broken in linux), and that even with higher polking rate on usb, the ps2 interrupts handled faster. Mouse ended up better as usb due to thruput issues with serial. Take care to find an uncorrected sensor output to avoid microjitter and variable response time. Only a few sensors do this, so finding mice by sensor is how I approached it.