Yesterday during my lunch break, I encountered a traffic message trailer that was apparently sampling traffic velocity with a 33.8ish signal (it tended to drift while I was completing my runs). I completed 3 passes (all that time permitted): First pass was Redline EX, FW 1.3 - Segmented 2,4,5,6,8 Second pass was the R3, FW 1.37 - Segmented 2,4,5,6,8 [Starts at approx 3:20 in the video] Third pass was running both (only to see if they would alert at about the same point where they initially alerted, and to allow others to hear the differences in their ramps simultaneously - routinely I NEVER run two RDs at the same time). [Starts at approx 4:40 in the video] Map of the course at the end of the video The first part of the video clip is lengthy, as I also experimented with the EX to: Determine how long it takes to fully power on the RD and then alert to a signal after the start-up beeps (approx at 1:30 into the video) Determine how long the EX would continue to alert after passing the source Determine how long the EX would alert to the signal as I pass the source in the opposite direction of travel I was going to post the above experiments for R3 as well but the results for distance after passing the source and in the opposite direction of travel were very close to the EX. Additionally the R3 pretty much powers up and alerts instantly. Here's the video: Conclusion: The EX hung really well with the R3, with the R3 alerting a few seconds prior to the EX. The difference between alert time on this course between Run 1 & Run 2 appears to be the distance between 1 set of light post, with both RDs alearting right around 3K feet from the source. Additionally, I have a new found appreciate to the time others have put forth to test, record and share their results!