Should we use sideral or tropical Astrology?
To answer quickly: both, keeping a close eye on the sideral option.
Which one works best?
Apparently the tropical works slighty better than the sideral, when we consider a equal 12-division of the zodiac.
But, it would work best if we would trace the energies for dozens of people born for each day and compare when does a sign ends and another begins.
To put it quickly: it would be something between the vedic/sideral and the western/tropical that would work better. We would consider (if you choose 12) a 12-division of the sky and you will find that approximately one sign shifts into the next one around the 24th of each month. However for some signs this transition only happens by the first day of the following month (ex: Sagittarius for me starts really in 1th Dec, and Taurus by early days of March) or even slighty further (for Cancer). Therefore, for me people born in late April, late June, and late November would be respectively Aries, Gemini and Scorpio.