Difference between retro and direct mercury -
Retro Mercury
Native gives more importance on intelligence and word/sentence/topic details. Native cannot tolerate criticism and tends to analyze micro details in matters. The native, during the childhood, does not know, when/how to start talking/communication. how/when to stop communication/talking,
Retro Mercury creates a constant fear in natives that they would do something wrong. e.g. during an online chat, they recheck spelling mistakes, before pressing the enter key.
When Mercury traveling reverse in the natal chart, person analyzes past situations to make/understand things better in future situations.
They do labor to collect all the required details regarding a topic before starting a conversation or making/typing a document/data-entry. They bother much about errors, happened in past, happening in present, going to happen in future, and, do not like mistakes in conversations, documents, notes, posts etc. Also, if Mercury is connected to 9th, they do not like to give wrong information to others. That's why they do drafting or rough work from all dimensions/angles and then do recheck everything before they are going to start.
This kind of 'go back and come again' 'reasoning' appears in humans due to a retro motion of the planet Mercury which is apparent from earth.
Sometimes, these effects would also appear in some persons even though Mercury is not in Retro in the birth chart. Vedic astrology says this kind of things can happen to any person during the Mercury retro transit. What if these effects still appear even when Mercury is Not in Retro during transit?
these effects can also appear if
- Mercury is influenced by any other Retro Planet, like, if
- a retro planet aspecting Mercury or conjunct with it
- if any other retro planet is a significator of 3/9 houses in the natal chart
Direct Mercury
This implies - those who have Direct Mercury, does not think/bother much about errors; and easily start talking and stop talking; and also, does not bother much about the past, present, future mistakes, errors in notes, documents, communications, etc. Direct Mercury gives the natural ability to go forward without bothering about side effects. e.g. during an online chat, Direct Mercury people quickly press enter as soon as they complete the typing.
Which is best, retro or direct, is not going to be a great topic for debate. Both cases, no doubt, have pros and cons (good/bad) in dealing with situations, events.
My opinion is when Mercury, direct or retro, gets good aspects (including conjunction) from beneficial planets (natural and functional), gives very good effects.