You mean NITDroid? It's not really a platform as it is a completely separate stock Android distribution tailored to run on the N900 hardware.

The NITDroid installer merely makes it easy to install the Android OS image and gives you a mechanism to dual boot your N900 into either Android or Maemo. However, the two environments are segregated and never contact each other.

As far as stability, it's just fine although installing an OS image to your SD card and installing a boot loader should not be taken lightly even if the install is highly automated.

As far as compatibility with the N900 hardware, the NITDroid team is making more progress every day, although I don't know anyone who runs Android on their N900 for daily use yet.