Yeah this monitor makes no sense, the panel is actually even older, since the first xl2420t had the same 144hz tn panel already. They just want to milk that old panel before new high dpi panels get released by AUO, which should be near the end of the year.
The colors and ppi on that ancient 144hz auo panel are abysmal. Ive recently bought a Dell U2515H for the office, which is a 25" IPS panel with 2560x1440 resolution, which also has a very light coating and its day and night difference. Unfortunately the Dell only can do 60hz, but maybe LG will release one day a native 120hz ips panel, that would be great.
Once you get used to high dpi monitors, going back to those ole 1080p 24" monitors is a huge downgrade for the image quality, esp. If those monitors also have an aggressive AG coating like all the 144hz tn gaming monitors oit there.
In fact, I think the best monitor would be a 4K resolution @25". Because with 1440p I can still see the pixels mostly on diagonal white font/objects. With the new Display Port standard 4k at 120hz is possible, so I hope they release such a monitor at 25". 24" feels a little too small to me, so I would either take 25" or 27" at 4k+120hz+adaptive sync or gsync+good IPS or Oled.