Hi Andrew, I use a 27" 1920x1080 monitor (Acer H274HL LED), and have not had any issues with the video for X1/X2. Both of your choices exceed that, so this is really up to your preferences (cost, performance, rating, table space, etc.). If it were me, I would also go with your 27" choice, as it yields more "pixel real estate." (the 29" is simply 600 pixels wider) Bear in mind also that your graphics card can play a big part of what makes the monitor "run well" too, so research that in tandem to an upgrade. Best regards, Michael