Hey I am in the same situation. I have 2 Sony monitors one a 19"(g410) and the other 21"(520). Of course running anything out of what they recommemd is usually not a good idea. But listen and think bout this, usually monitors say for example 1024res will run at 85hz where 1280 would be 75hz or 60hz, so it seems as if certain resolutions could run higher like say 640 should be safe at 100hz since if you follow the way the HZ plays on the different resolutions.
Now my thinking would be this, my 21" monitor will run at 1880X1400 @85hz. Why then would they cap it at 85hz all the way down at 640x480? Wouldn't you think if the monitor is strong enough to run at 1880 @ 85hz then lower resolutions should be able to run 100hz no problem. Like 1024 or 1152? What do you guys think, its always bothered me that the Sonys are stuck at 85hz regardless of the resolution , compared to other brands that as long as you lower the res enough you can hit 100hz. Now I am no monitor tech but the only reason it seems like it would hurt the monitor is if the Sony's had some sort of monitor refresh piece of hardware in them that is not designed to run over 85hz. If the sonys are built similar to others , it seems all I would have to do is lower the resz to hit better HZ.
What do you guys think?