Regarding my own experience, I've known about both since the mid-90s but have mostly studied Abraham with occasional listenings to Bashar. In the past year, I've been studying Bashar fairly intensively as well.

In essence, many of the ideas between the two are similar in intent but are often different in approach, analogies used and language offered.

In my opinion, I think there are two absolutely core differences between the two from which all the other differences stem.

Core Difference 1

Bashar is a physical extra-terrestrial individual (a Sassani) from what we would perceive from a linear perspective as our future, although currently being channeled through Darryl Anka (Remember that past, present and future are all happening now).

Bashar has mentioned a few times that s/he regards Mr Anka as a past life of his/hers and has said that the time is coming (within the next century) when humans will be able to physically interact with members of the Sassani race.

On the other hand, Abraham is a purely non-physical group consciousness that effectively lies at the core of all consciousness. In a sense, you could say that they are the inner beings of inner beings.

That basic difference in perspective (physical vs purely non-physical) is what leads to many of the differences in the detail and kind of information that is offered.

If you watch Abraham seminars, they are purely focused on processes of manifesting and understanding the operations and implications of the Law of Attraction. There is little material relating to the actual mechanics of daily physical living and Abraham often joke that they only have one answer to everything...which is the Law of Attraction

Abraham will always tend to relate every question asked back to an understanding of this Law of Attraction.

Bashar seminars, on the other hand, tend to go into much more detail regarding physical living, physical processes and physical technology.

So, for example, if someone asks Abraham how to be more physically healthy, they will respond in a manner relating how one's dominant thoughts attract manifestations of health and how to more effectively align the desire for health with your dominant thoughts ("beliefs") about it.

Bashar, on the other hand, while still providing a reality creation background, is more likely to give you a list of things that would be beneficial to eat and physical things to do to stay healthy.

Core Difference 2

Probably the other core difference is that Bashar says there are Four Laws of Creation:

• Law #1 You exist

• Law #2 The One is the All. The All are the One

• Law #3 What you put out is what you get back

• Law #4 Change is the only constant, except for the first 3 laws

Abraham say there is really only one Law in the Universe worth speaking of...

• The Law of Attraction - "That which is like unto itself is drawn"

If you look closely, you will see that Bashar's Law #3 is actually The Law of Attraction also. And if you give it some thought, you may notice that it is the only one of the four we can physically do anything about.

So Abraham's stance becomes clearer in only focusing on this law since they are always focused on practicality rather than theory. They refer to themselves as being "an endless spewer of processes"

But Bashar is much more willing to talk in detail about the actual mechanics of how the laws work.

For example, Bashar will often refer to the idea of how rapidly flipping through static disconnected parallel realities can give the illusion of a continuous evolving universe much like an animator's flip book giving the illusion of a movie.

And many of Bashar's ideas and advice involve relating how one may move to different parallel realities in order to experience desired outcomes that exist there.

Abraham's ideas are very similar (if you look closely) but they tend to keep all these subjects at a much broader and less technical level. I've noticed for years that they seem to be ensuring that their message is as basic and simple to understand as they can make it in order to help as many people as possible relate to it.

I get the impression that Abraham seem keenly aware that they can allow their message to resonate with a much wider audience by keeping it simple in this way and, at this point in time, the teachings of Abraham are (worldwide) vastly more popular than the teachings of Bashar.