Caltrac operation on leaf springs

This thread intrigues me. I have a new set of Cal tracks and the mono leaf springs that I was going to run on my 70, but I have been told that they are not really good for street use. Can anybody elaborate?

I've been mulling over this as well trying to decide whether to go with Caltracs or Ladder bars/coil overs. It seems pretty split as far as what folks recommend. There are pros and cons to each. I have driven as car with caltracs and think they're fine for street use.