I liked the ORIGINAL Intellistar (not XL) icons, from 2007.
They look very good in HD, but they were replaced in SD because they just weren't clear enough. Precipitation, in my experience, often looked like a hazy grey blob with smaller blobs falling from the clouds. On a 19" TV I honestly had a hard time telling whether the precipitation was rain, snow, or a mix, and, living in Massachusetts, that made quite a difference. The smaller the icons got, the harder it was to tell just what was falling.
Yes, they're very realistic, but the clarity in SD just wasn't there, which is why they were replaced. Honestly, I don't see anything wrong with the current SD graphics. They're not as realistic, but they're very clear, and
that's what's essential in communication.
That said, now that I have access to the Intellistar 2, the realistic icons look fantastic, and there's no confusion about what kind of precipitation is being shown.