I got a XB273K and was going to replace it due to very bad yellow bleed, but decided to step up to the X27 instead since I was very pleased with the XB273K except for missing the "real HDR" experience.Since I have cycled through the XV273K and the XB273K, I can give some comparisons between the three Acer offerings. Note that all three had good signal input response times, although the pixel response of the XV273K really let it down.Scroll to the bottom for the X27, since I am going in increasing order in price (and the order in which I purchased them).XV273K ($800-$900):+ Supports Freesync for AMD GPUs/Gsync compatible with Nvidia GPUs+ 144Hz 10-bit 4K available with two cables+ Same panel as the more expensive XB273 with high DCI-P3 color coverage+ 2 HDMI inputs + 2/1 DP 1.4 inputs+ Good calibration out of the box= Can't use dual cable with HDR or Freesync. It can bug out and say it's doing it but it doesn't actually do it.= Freesync and HDR only available together using an exploit through the Acer desktop app.= Backlight strobing available but the bottom 33% of the image had double images due to slow pixel response- Very poor overdrive. Light colors smear into dark colors due to excessive >12ms transitions even at Extreme setting at 144Hz- Poor backlight uniformity, left/right edges were dimmer.- Freesync locks overdrive to Normal which is even slower, so even worse motion quality.- Slow OSD- HDR experience was poor due to lack of FALD and HDR switching was manual through the slow OSD or the desktop app.XB273K ($1150-$1000)+ Very good overdrive tuning. No smearing at all where the XV273K fell short.+ Automatic HDR switching without fiddling in OSD+ Easy to limit display to SDR color space in SDR mode, HDR color space in HDR mode+ Good calibration out of the box= Gsync only= Display maxes out at 120Hz 8-bit over 1 DP cable and only 1 HDMI available= Variable global backlight barely does anything, but it doesn't hurt- Mediocre HDR experience due to lack of FALD, but at least it wasn't fiddly- Poor backlight uniformity, left/right edges were dimmer and my sample had yellow bleed on the right.X27 ($1800-$1650)+ All the positives of the XB273K+ 384 FALD zones can give very deep black tones while blasting 1000 nits out of another zone.+ Good FALD speed. No problems in games or movies.+ HDR experience in games is one of a kind. It's impossible to capture it, so you have to see it in person.+ Even SDR looks better due to the contrast boost. Mostly fixes the IPS glow problem and other uniformity issues associated with edge lit backlights.= Overdrive "Normal" is even more aggressive than the XB273K and cause a little overshoot. Not that big of a deal since you really have to look for it.= The haloing doesn't seem that bad even on the contrived LG OLED demos but that could be due to astigmatism causing bright lights haloing for me IRL. Haloing is definitely worse on the edges due to worsening contrast ratio there.= Extremely expensive, but think of it as a high end TV stuffed into 27" to fit on your desk.- Small light colored desktop elements surrounded by large black patches can look dimmer than intended due to limitations of the FALD zones. You may want to turn off FALD for critical work in SDR.I can't tell you whether it's worth an additional 65% over the XB273K but I figure if I'm going to spend nearly $1000 on a monitor with flaws, I might as well stretch for the best and avoid the headache.Edit: Added FALD SDR comparison + SDR haloing demos