Breast augmentation plastic surgery is performed to enhance the breast size and shape due to congenital abnormalities, a lack of development, changes or asymmetries following aging, weight loss, and/or pregnancy. Now, there is one other thing that you may have considered when asking your surgeon about having your replacement and revision complete. For women with moderate to severe breast sag or other asymmetry, a breast lift (mastopexy) may be recommended to ensure the best result and longest lasting result. Failing to have a breast lift when necessary will only lead to a less than ideal result leaving the patient unhappy and needing a revision surgery. A larger breast implant can help lift the breast, but the low hanging breast tissue will still be present causing a disconnect between the implant and breast tissue located at the bottom of the breast.
Although your breasts remain visibly asymmetric, there is improvement over your prior appearance (unless your body is slightly turned in the first photo). Your best course of action is to have a frank discussion with your plastic surgeon expressing your dissatisfaction/frustration. He or she may offer some other alternatives, or additional procedures that can be done to further symmetrize your breasts. Only he/she knows exactly what work has been done and if there is room for further improvement. Good luck!
Given the pre-existing asymmetry, you will need to accept that they will never be perfectly symmetrical, as no breasts are. You may consider nipple repositioning, possibly with a Benelli lift. Perhaps downsize the left implant and tighten the pocket. It would be helpful to know it there is any animation distortion on that side.
Although I can appreciate significant improvement after the revisionary breast surgery, I can also understand your concerns: a significant degree of breast asymmetry and breast implant malposition still remains. Ultimately, whether to undergo additional revisionary breast surgery or have the breast implants removed will be very personal decision that only you can make after careful consideration of pros/cons of each decision.
If I were seeing you in consultation to discuss revisionary breast surgery, additional capsulorapphy (adjustment of the breast implant capsules) would likely be very beneficial. Best wishes.
I think that you have to be very specific about what you are looking for. Your breasts started out very asymmetric to begin with.