Hi, Ully.
I struggled with the same problem a few months ago while researching a new monitor that would not bottleneck my system. Long story short, I finally concluded that almost all of my computer usage involves motion on the screen, mainly gaming; so, I decided to get a monitor that was built for motion---a super-fast monitor that would not ghost, blur, or artifact.
I think that maybe you’re headed in this direction, too. BenQ has a great reputation, and I’m sure it will be dependable. It is going to handle gaming and motion better than the LG. And its color reproduction with static images, though inferior to the LG, will still be OK. And you get more real estate with the 24 inches. But BenQ is known for their 120hz monitors. Is the one you chose 60hz? (The only reason I studied BenQ when I was shopping for a monitor was because they specialize in 120hz.)
The LG’s 22 inches at the same resolution is going to yield a crisper image, not only because of the in-plane switching but also because of the higher pixel density. But 22 inches is pretty small. You have a strong PC. If you connect your GPU to the LG with a dual-link DVI, I’d guess that you will experience very little ghosting. HOWEVER, I’d also bet that with some games you will experience SOME ghosting on some occasions.
What would I do? 22 inches is too small for me. Motion reproduction is more important than color reproduction. I value a monitor that will not bottleneck my system. I’d get the BenQ; HOWEVER, I would insist on 120+ hz.
Also, consider this: Get a fast TN monitor first (a BenQ). Then, save some cash for a second monitor later. Perhaps your second monitor (nine months or a year down the road) can be an IPS monitor.
Good luck with this. I’ve been very happy with my Asus VG248QE.
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i7 3770K OC @ 4.2Ghz / ASRock Extreme 4 Z77 / evga FTW 670 2X-SLI / Creative SB Audigy SE PCI Sound Card / 32 GB Corsair Vengeance 1600 / 128 GB OCZ Vertex 4 / 2 TB WD Caviar Black / 2 TB Seagate Barracuda / Asetek 510LC Liquid Cooling System / LG 14X Blu-ray R/W / Corsair 1000w PSU / AzzA Genesis 9000 full tower / Windows 7 Professional 64 / 144hz 1ms 24-inch Asus monitor