Not happy with results of 6 month smile. Should I see somebody else and will I be able to get a better result? (photos)

There is only so much that can be done in a short amount of time, so 6 Month Smiles should not be compared to what can be achieved with comprehensive braces.  The goal of a 6 month time frame (even the 9 months you got) is merely "significantly better".  I would say you got that.However, you COULD get "better".  But you must clearly define what you don't like.  Porcelain veneers can also be considered, as that would give control of the size, shape, and color of the teeth, and in only 2-3 weeks.

You still have rotation on your upper centrals and lateral.  This can be fixed but needs more time to do it correctly. Your case looks to be an improvement but treatment is incomplete. I would pursue a consultation with specialist who should be able to improve your result.

It would be very surprising to hear of an orthodontist using 6 month smiles. Was your original treatment done by a general dentist? 6 month smiles is a limited ortho treatment used by general dentist typically to correct only front teeth. I would definitely suggest going to see an orthodontist and getting it done right and I would also suggest speaking to your previous doctor to clear things up. I don't think you should be paying for 2 treatments when it should have been done correctly the first time.
I do agree that while your smile has improved it needs some finishing touches that are common practice with orthodontist such as taking progress radiographs to reposition some of the brackets and add needed finishing bends to get the teeth just right. This is one of the major drawback of 6 month smiles.