Self ligating braces use less pressure on the teeth, from what is pitched.  From what I understand... self-ligating braces will move teeth initially more than traditional bracketed braces and hone in slower... where traditional braces move I've heard move teeth slower at first and quicker at the end.  Sometimes I hear the evangelists of Damon preach that they can replace RPE?  Is it true???  Here's what the Ormco website shows:  https://ormco.com/products/damon-system/studies/freedom.php   With the RPE being the big gorilla in the room.. it's no wonder it gets attacked from many angles.  Does it deserve it?  I think it depends... If you're moving 2-3 mm with an RPE for phase 1... it seems that braces would move dentition that far just fine without the ripping apart of sutchers.  Obviously this depends on age.  If, however, you're going around 9 mm... well... let's take a look at just that.  We're looking at the #6 tooth.  In the before plaster... the teeth looked to be placed more central in the gum mounds.  In the after... the teeth surely moved out, though the gum mounds don't look as balanced on both sides here.  That's for 9 mm on a mixed-dentition kid... so phase 1.  Maybe 6 mm might be about what makes sense.   I'm not going to call the spot as truthfully it depends on a number of factors.  The person doing it... their track record and history, age of patient (younger has more skeletal movement), whether they monitor teeth shooting from bone and teeth coming out from gums.  Typically, people overexpand then retract.  I don't know the particulars of this kid's teeth... but knowing that periodontitis may be exacerbated by less gum support... I'd probably be a little on the conservative side.  When you hear mm... to give a perspective... a U.S. nickel has a thickness of 1.95 mm.  For adults... the movement won't be so much skeletal as dental.  Though, there may be some associated skeletal movement.  It's unknown to me, though I'm sure it's been studied.

Some practitioners have tried Damon braces and just have not had success.. Some use Damon brackets exclusively and swear by them.  Some of those who don't like them say that they're too hard to control the finish for.  I have an inkling that Carriere has addressed this concern.  I have seen phenominal finishes with Carriere... though I don't know if that has to do more with the practitioner or the bracket system.  

Things to watch for: Because self-ligating brackets allow more flow and movement (or at least claim this which is disputed by some of those who use regular brackets)...  I think that there is evidence of less pressures, so we're discussing degrees of pressure here.  Does this translate into a difference of root absorption?  At least one published study has shown no difference between the 2 types.  If there's a jaw-size discrepancy... then often in the end results there may be an exacerbation of asymmetry.  I find that the patients who undergo self-ligating braces tend to either have a gathering of teeth on the left or right side of the face or sometimes in the middle.  One, in particular, seems to have all his patient's left sides of the face's smile (talking lip here) a little less pronounced the the right.  This appears to be a training issue as this person is a dentist and in orthodontic school they talk about what angle to approach the patient.  12 o'clock or switching side to side so that one side is not always preferred when visiting the patient can help to alleviate some of those types of problems.  Never-the-less... for many after photos with Damon braces, I do see a convergence of teeth in the smile for some practitioners - not all - and it can and does vary per patient.  The types of things to watch out for initially are a smaller arch distancing between maxilla and mandible on one side or an asymmetric arch length.  Obviously, a panoramic typically is visually skewed, though a gross discrepancy may display.  Does this mean that you will have problems?  By no means... It's just something to be aware so if concerns are there, they may be discussed.

I have a personal belief that a self-ligating system may be better in treating adults... but this is highly operator dependent.  It may just be that more curious orthodontists are more likely to accept newer technologies and it could be more of a reflection on the practitioner.  Personally, a practitioner who uses Damon braces AND does RPE if needed is someone who is a thinker.  I like that.  Orthodontic staff have floated that the checkins may also be less frequent with Damon braces...  which can effectively stretch office visits... thereby decreasing $ expenses.  However, that has also been countered by those who say that it is dependent on the practitioner's set scheduling.  Due to the lighter forces used... I personally would tend toward a self-ligating system.  

More importantly, I'd look to see if the practitioner was someone who I trusted.  :-)