Since I don't use signs (or any (sub)division of the zodiac circle) at all, I don't use Sun signs either, but I'm reminded of what Kim Farnell once said in an interview.
The interview wrote:Q: What is your attitude to sun-sign columns?
They are to astrology what first aid is to medicine.
http://www.skyscript.co.uk/farnell.html
Perhaps I'm going a bit off topic (since the initial post is about what individuals with a particular Sun sign would think when looking for a partner) but since I only use aspects I would (also) look at aspects between Suns in natal charts of potential love partners.
Now as far I know, in basic Sun sign dating astrology people looking for their match would look at Sun signs of similar element, Aries looking for Leo's/Sagittarians etc. My question is how does the Sun sign/elements-matching deals with the possible fact that A's Sun in 29?59'Aries and B's Sun in 0?01'Leo are in trine aspect by sign but in square aspect by geometry? Would the former be the most essential or the latter?