Hi,
I recommend you going for the NEC. It will display absolutely all AGA modes (not the A2024), and in addition it has digital control of picture size and position, so you can adjust the screen for each resolution. The monitor will recall the appropriate settings automaticly when the resolution changes.
A funny thing about this monitor is seeing how the sync changes. Typically, a monitor will blank the screen for a moment and the image will come back when it has adjusted to the new frequencies. The NEC 3D does not blank, it shifts the sync until it finds the correct one, and the effect on the screen is curious to look at.
A problem occurs with PAL and DblPAL, and NTSC and DblNTSC. Both modes produce the same resolution but the image size is different. Since the monitor stores the screen settings by resolution (not by frequency), adjusting the screen for PAL mode overwrites the settings for DblPAL. The same goes for NTSC and DblNTSC. Happily enough, the NEC 3D has two banks of memories, selectable by a switch. You can store two settings per resolution and switch them back and forth, so you can work around this problem. Another problem, common to most VGA monitor under DblPAL/NTSC modes is that the image will look narrow, even if you adjust the monitor to its maximum width. You can work around this by using all horizontal overscan.
Beware, it is a *heavy* monitor. If it is to be shipped, it could cost you some more Euros/Dollars than you initially would expect. Check cost of shipping before you engage in the purchase.
That's all I can recall of my good old NEC 3D, my favourite monitor, which was put in store after I bought a Mediator/Voodoo3 and a TFT flat panel.