Lately I came across quite a few posts where people are mentioning they have set 59Hz refresh rate, instead of 60Hz, and are they claim that helped with eliminating the micro-stutters. I'm curious is there any technical reason that would actually work or is it just another placebo effect we all know and love :)

Difference between 60Hz and 59Hz?  It's about 1Hz 

Sorry - now that's out of the way (couldn't help myself) let's talk about the actual question you asked.  From Microsoft:

Quote

Certain monitors report a TV-compatibility timing of 59.94Hz. Therefore, Windows 7 exposes two frequencies, 59Hz and 60Hz, for every resolution that is supported at that timing. The 59Hz setting makes sure that a TV-compatible timing is always available for an application such as Windows Media Center. The 60Hz setting maintains compatibility for applications that expect 60Hz.

In P3D terms, I would expect it to have very little effect.  V-Sync will be limited by a single FPS, that's all.

Appears to be a placebo on my system.

These monitors go to 60...

I have seen it reported (here) that this helps enormously to remove micro stutters 'some' systems.  However, I can't say it did anything for me. Maybe it helps when these stutters are severe. I'm getting such good performance with v4, that I doubt I'd see the change if it were present.  If it helps some though, that's great!

The part about tv compatibility got me to thinking, I'm already using a 40" Samsung LED TV as my monitor, so there is no need for tv compatibility.  I guess that is why I have not noted a difference as of yet.  Any thoughts on this beside my own?

Having some experience in r/w television engineering, I know where the 59.94 Hz comes from - but I don't think this could have the effect that some claim.

This goes back to the days of analog television using the NTSC standard, which generated 59.94 interlaced video fields per second, rather than exactly 60.

The field rate was originally exactly 60 in the days of black and white television, which made it very easy to lock to the 60 Hz AC power line frequency in the U.S. 

When color broadcasting was developed in the early 1950s, the frame rate was slightly lowered to prevent stationary patterns from appearing in the video due to interactions with the frequency used for the color subcarrier.

In any case, this has no relevance to digital video. The 59.94 timing is available on some digital monitors in case they are used to display original NTSC-encoded analog video (with a converter).

I'm pretty sure the claim that using the 59.94 refresh rate could improve microstutters in purely digital video is in the "urban legend" category.

1 hour ago, JRBarrett said:

Having some experience in r/w television engineering, I know where the 59.94 Hz comes from

Interesting Jim, I love trivia like this.  Maybe it's because I'm old enough to have worked on tube equipment, heck I even got a 1st Class FCC License before the FCC did away with them.  Agree, impact on the fluidity of animation for a flight simulator would have to be unexpected.