I have always used the modular version for X11_TYPE. However, I do have the occasional stability problems, particularly when I resize a pseudo-terminal.
I'm using Amd64 Current (9.99.17), but this has happened across a variety of builds and it always causes X11 to dump core. The CPU is a Core2 Duo P8600 and G4X Intel graphics
Do people have views on which is more stable? In an xconsole I get frequent warnings about "Potential atomic update failure on pipe A: -35." This comes from intel_sprite.c:132. There is an "ifdef __NetBSD__" line and I don't know if it's equally relevant to both native and modular builds.