If they are old that means automatically that are worse than newer monitors? I want to hear like pro and cons so i can decide which is better for me please.
No, just worse value.
The VG248QE uses PWM backlighting which may cause more eyestrain. The XL2411Z doesn't have DisplayPort. Both of them have HDMI implemented with reduced bandwidth so it can't be used for >60 Hz, which can limit flexibility, since adapters can't be used to connect to Dual-Link DVI or DisplayPort (this is more of a problem for the BenQ since it doesn't have DP, and can only accept 144 Hz over DVI). And the panel in the XG2401 is generally a bit better looking. The Samsung will be much better looking, since it has a VA panel which will give deeper blacks, and a wider gamut backlight, but I assume it's more expensive than the others, and the curved panel is not appealing so some people.