I had two monitors that were x1200 but sadly they both stopped working for mysterious reasons. It was great for online poker as it allowed a perfect number of tables at a decent size (Stars, FTP). In the end I played only 4 on each as that was my sweetspot for paying attention to all details but for massgrinding 12 on each was doable (iirc, I could never play more than 8x2 without going insane).
Standard x1080 didn't work well at all especially back in the day when the tables weren't resizable :D