Currently on PRAD has the necessary equipment to properly test monitors signal delay (input lag) and pixel response times accurately. PRAD's review will be available to the public on June 10th, 2013.
PRAD measured a signal delay of 1.6ms and 3.4ms pixel response time average at 60hz using the Trace Free 60 setting. There are many 1920x1080 IPS/PLS panels with similar signal delays and slightly pixel response time averages (5-10ms typically). Setting the Trace Free to 80 further improves the pixel response times, however PRAD only tested Trace Free 60 in their review.
The VG248QE won't break any records in terms of its 60hz performance, but it is still essentially delay free and can be used for competitive console gaming, however I would suggest that competitive console gamers get an IPS/PLS panel such as the Eizo EV2336 or Asus VG23AH for competitive console gaming since they also have negligible input lag and very little ghosting.
At 144hz PRAD measured a 0.7ms signal delay and 1.7ms pixel response time average using the Trace Free 100 setting...I'm not sure why they chose to only post the Trace Free 100 results because they recommend using the Trace Free 40 setting at 144hz.
Subjectively, at 60hz the VG248QE feels very similar to my Samsung 700NF CRT. When Lightboost/3D, 120hz and 144hz are enabled the Asus feels even more responsive vs. my CRT.
Blue=Suitable For ALL Enthusiast CRT & 120hz Users
Purple=Suitable For Some Enthusiast & ALL Regular Gamers
Orange=Not Suitable for Enthusiast Gamers & Some Regular Gamers
Red=Not Suitable for Enthusiast or Regular Gamers: CASUAL GAMERS ONLY
Asus VG248QE: Signal Delay=1.6ms @60hz and 0.7ms @144hz measured by PRAD
Dell U2713H Game Mode: 14ms (Measured by PC Monitors Info)
Dell U2713H: 30ms signal delay measured by PRAD
ViewSonic VX2770SMH-LED: 4-5ms
Asus PB278Q: 17.8ms signal delay measured by PRAD
Dell S2740L: Negligible
Asus VG23AH: <5ms
CrossOver 2720MDP Gold: 12-14ms
Samsung S27A850D: 13.6ms signal delay measured by PRAD
Samsung S23A700D: 12-13ms @120hz
BenQ XL2420T: 3ms @120hz
Asus VG236H: 3ms @120hz
Asus PA238Q: 2.2ms signal delay measured by PRAD
Samsung S27A950D: 13ms @120hz