Was there ever consensus on whether the fail modem on the N900 was a software or a 100% hardware issue. If it is a software issue the new modem blob will hopefully fix that, if hardware I hope that the new manufacturing run will address that.
I think the new lead free PCB soldering/tinning process has been improving but it is at least partly responsible for problems on the N900 like the USB port and possibly the modem coming loose and requiring pressing down.