I have 0.4.6-1. Seems to work well. It doesn't do much, but it puts two bars of five squares each in the status area, the left bar indicating cpu usage and the right one indicating memory usage.

I find it a useful indicator for when the N900 is under heavy load. I see no alternatives either..?

Bottom line seems to be that it's perfectly ok to leave it in extras, if the only criteria for being there is that it doesn't break your device. One would hope the criteria for QA are more rigorous than that, though.