If your load hit 50%, and there are these latancy issues, it would definitely behoove you to upgrade the memory in a prudent time-frame. Wouldn't want a crash.
No you don't get it. I mean a load of 50, not fifty pecent, like when you do a top, w, uptime, those load averages, well, the box hit FIFTY coz it was swaping so much. Nonetheless, BSD does not crash, ever. If it WERE to crash, UFS/FFS is a robust filesystem, and I do daily backups of the database. You would need to take an axe at the box to take it down.
*puts on asbestos flame-retardant suit*
Now I've had Linux crash on me several times though...