In my meager experience with these companies, I have come to the
opinion that they generally are very predatory. They are not like land
based car towing companies at all, or depending on your opinion of
those, at least they are much worse. I think it's because of the
existing marine salvage laws which are so biased towards the salvor.
This is key, I think. You need to consider them as salvage companies,
not towing companies, for indeed, this is what they are.
Ironically, I think the best defense against these salvage companies
is to buy "insurance" from one of them. But if the assistance you
require doesn't fall into the criteria covered, you may end up in a
salvage situation and end up paying a lot of money anyway. They could
take you to court and charge you a significant fraction of the value of
your boat, like 25%-50%.
As to preference, in my own experience, I had bad dealings with
SEATOW in the FL keys a couple of years ago, so promptly went out and
purchased insurance with TOWBOAT U.S. and have kept with them ever
since. I have not needed this insurance since (go figure), but my
general business dealings with them have been positive. They messed up
once on my insurance, and long story short, I basically ended up getting
almost a free year of $350/incident coverage, and all it took was a
phone call.
I have found SEATOW to be the most predatory of the bunch. (I guess
someone has to be worst) Previous postings on this topic seem to
validate my own findings, though someone's own personal experiences may
differ.
Why would they be worse? My own thoughts are the structure of the
organization make it so. The operators are basically independently
owned, operating under license from SEATOW, and really have nothing to
do with the company. I'm sure some of these are very reputable, but the
chance of getting a "rogue" operator exist, and this is how I consider
the one I delt with.
Finally, if I became aware of a company that could guarantee they
were a towing company only and not a salvage company and that they did
not do salvage, well, I would go with them.
Hope this helps.