I have been doing more reading than operating recently. I have spent a week reading Array of Light by Tom Schiller N6BT. This book is unique in correlating on-air performance with the efficiency and design of antennas. Tom does say any antenna will work but endeavors to explain how a few db can make a difference in performance and enjoyment. I recommend the book. Bear in mind much of the book is devoted to yagis. many of us are not going to have one. However, the best part of the book for me is the discussion of verticals used near or over saltwater. Tom says a vertical in that situation can be better than a yagi.
The shocking thing for me is I was ready to conclude that the antenna and efficiency is not as important as some say. In other words my rate of QSOs does not seems to increase dramatically with one antenna or another or even power level. Bear in mind most of my operation is portable and my goal is just to make some QSOs. The rate of QSOs seem constant at four or five an hour. I will ragchew any chance I get. The QSO rate can be higher and it just depends on whether there are other stations out there who want to work me. For example, my best rate of QSO was 13 per hour when I operated the Peanut Sprint at one watt. There were many Georgia stations there ready to work me. So I was ready to say opportunity and conditions are significant drivers and ultimately the operator is probably the most important factor. I have heard of DXCC holders that did it with QRP and even with attic antennas.
Now perhaps I have been already following some Tom's advice on antennas as my wire antennas tend to be long relative to wavelength and somewhat high. I also get them in the clear and often near saltwater. The smoking gun for me is my use of 28 gauge ribbon cable with two conductors in parallel. There is loss in the resistance there but does not seem to bite me too bad. That ribbon cable is so convenient and easy to deploy. I also use tuners and baluns I can't say what the loss they have.
I think there is a mental factor to portable antennas. I started out thinking the Alexloop could not be a serious antenna. I eventually got past my mental handicap and enjoy that antenna immensely . I am blown away with 40 meter QSOs on the Alexloop where it is 15% efficient. I say be careful not to get "Blinded by Science." I will admit that I benefit often by the other station having a killer antenna. However, it seems I end up also working stations with antennas in the attic. So go figure.
Fortunately, there is lots of fun to be had operating portable with antennas that are less efficient than a dipole or a yagi. I don't think this necessarily disputes Tom's argument on efficiency. Perhaps I will use that dipole with 14 gauge wire and low loss feedline more often. It just takes three supports to do it, I usually get away one or two supports or just a tripod with the Alexloop.
Tom has definitely convinced me to do more with verticals near salt water. I think I will try resonant verticals near saltwater with gull wing radials. I have access to state parks on the Gulf Coast of Florida and that is just too much of an opportunity to pass up. I have enjoyed and learned much from Array of Light. Thanks for a great book Tom.