I have the RS Discone, and I am happy with it, but it is the only one I have ever had, so I am unable to say whether or not it is better than another, though the Diamond seems to get lots of press.
I also have the RS wide band, it operates poorly for me on almost all bands....My modified RS mag mount works much better.
If you are still monitoring this, I did pick up one of those extendable RS portable antennas, and on my Pro 97, while sitting on my deck, I seems to be doing a pretty good job with most bands.