Would an upgrade from 535cc to 700cc be a significant observable difference?

Dear Texan,   Front and side view pictures would have been helpful. You did not provide your chest and breasts circumference measurements in inches , which is critical for correct implants size selection , as per your desire.   In any event , increasing implants size from 535 cc to 750 cc,  means enlargement by 215 cc. For chest circumference of 32 , you breast will increase by almost 2 sizes , which is very significant. For 34 - one and half  size increase. For 36 - one and a quarter increase and for 38 - one size increase.   As you can see from all these options,  the implants size exchange will, indeed, create a noticeable change in your breasts cup size. You will need , though, capsulotomy (scar release) , to make room for the larger implants.   Always, consult with experience board certified plastic surgeons who operate in accredited surgery center for your safety. Most importantly, check the before and after pictures of redo breasts augmentation in the photo gallery, to make sure that they are numerous, consistent and attractive with nice cleavage, perky, symmetrical and natural looking.                   Best of luck,                                 Dr Widder

Dear PlasticMONSTAR,breast implant type and sizing selection is a complicated process and requires a detailed consultation that includes a discussion of your goals, a detailed examination, and a lengthy discussion. But the decision will always start and end with the patient. When it comes to sizing, we have all of our patients find 3 photos of their desired breast size. We ask for naked breast photos because clothing can obscure the true size (push up bras). Next, we consult with patients and go over the photos and take detailed breast measurements during a physical exam. Next, we using a sizing algorithm to determine a range of implants that will work based on the exam and the measurements.Lastly, during the operation, we use silicone sizers in the operating room to see how the size actually looks in the breast. We sit the patient up in the operating room, while asleep of course, and compare the sizer result with their desired look photos. If it is too small, we start the process over with a slightly larger implant. We don't stop until we get the perfect match.Of all of my breast augmentation patients, every one of them has been happy with their size due to this detailed and meticulous process. You don't want to invest time and money into a result that is either too big or too small.You should discuss your concerns with a board-certified plastic surgeon and make sure that your surgeon understands your goals.Daniel Barrett, MD
Certified, American Board of Plastic Surgery
Member, American Society of Plastic Surgery
Member, American Society of Aesthetic Plastic Surgery

Thank you for your question. This increase in the implant size should account for at least a full cup size increase, so you should definitely see a difference. Again, you should have a careful discussion with your plastic surgeon whether a 750cc is appropriate for your particular body frame and if your tissues can accommodate such a large implant. Good luck.
Sincerely,
Olga Bachilo, MD

My best advice: more communication.
It is definitely worth spending more time (prior to the date of surgery) with your plastic surgeon to discuss further.  As you know, it will be important for many reasons, that you feel comfortable that you and your plastic surgeon are on the "same page" prior to proceeding.  Show your plastic surgeon what you mean by your goal of "significant difference" using as many visual age (such as goal photographs) as possible. As you can imagine, subjective terms can be interpreted differently by different people. This additional communication will go a  long way when it comes to helping alleviate your anxiety prior to proceeding.
 Generally speaking, the best online advice I can give to ladies who are considering revisionary breast augmentation surgery (regarding breast implant size/profile selection) is:
1. Concentrate on choosing your plastic surgeon carefully. Concentrate on appropriate training, certification, and the ability of the plastic surgeon to achieve the results you are looking for. Ask to see lots of examples of his/her work.
2. Have a full discussion and communication regarding your desired goals with your plastic surgeon. This communication will be critical in determining breast implant size/type/profile will most likely help achieve your goals. 
In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. Again,  I have found that the use of words such as “natural” or "D or DD cup” or "significant difference" etc means different things to different people and therefore prove unhelpful.
Also, as you know, cup size varies depending on who makes the bra; therefore, discussing desired cup size may also be inaccurate.
3. Once you feel you have communicated your goals clearly, allow your plastic surgeon to use his/her years of experience/judgment to choose the breast implant size/profile that will best meet your goals. Again, in my practice, this decision is usually made during surgery ( after the use of temporary intraoperative sizers). Viewing the patient's chest wall in the upright and supine positions, with temporary sizes in place, help select the best breast implant size/profile for the specific patient.
I hope this helps. Best wishes.