We have done a fair amount of testing with our ham radio gear on the various antennas, plus some "practical" testing. I tend to favor the Digital 8' series with a soldered on PL259 fitting. There are some good studies which show that the easier "press/clamp on 259's do not give as good performance as a good solder job. This was brought home with several boats which all had the same AIS recievers. One boat was getting signals at 25 miles, the others were at about 12 to 14 miles. The only difference was that the better reception was a well soldered connector vs the screw on clamp on cheaper connectors. The mini connectors of the Digitals are not quite as good as the properly soldered on PL 259's. I found that the SWR of the Digitals were more likely to be close, than the Shakespeare. I take an antenna analyzer with me to the store when I buy an antenna, and have found some antennas which were quite a way off. Go with the best quality of exterior paint--some of the cheaper fiberglass antennas, get "fuzzy" in a few years.
I also prefer a good SS mount to the plastic mounts. (I have to replace the plastic mounts on the CD 25--it has become warn and sloppy.).
I have a top of the line Shakespeare and Digital on the Tom Cat, both are driven by almost identical radios, and I always seem to get both better reception and transmission on the Digital. But just my opinion...After all, these are just a piece of wire--some with tuned stubs. But a poor installation job can negate a good antenna.