There's a lot of great information here and I agree with 95% of it.
In my San Francisco area practice we've used almost every incision and placed implants in every plane. It depends on the patient.
It appears you're addressing two different issues. One is where your implant sits (under the muscle, above the muscle, "dual plane" (both)) and there are advantages to and negatives for each choice. For most patients under the muscle or partially under the muscle is the most appropriate choice. Typically the "under the muscle" implant is never fully under the muscle except with relatively small implants (typically the inferior edge of the implant is exposed).
The second issue is which incision will be used to place the implant. Again, good and bad things with each choice.
It is important to note that the TUBA approach (through the belly button) in addition to only being able to be used with saline implants, may void the warranty on many implants. This means if your implant ruptures you may not be covered by the extensive warranty that usually protects you.
Make sure you have an in-depth conversation with a board certified plastic surgeon before you make a decision.
I hope this helps!
