I have 500cc silicone cohesive- they feel harder - I hate it. Slight symmastia: pockets were made TOO big. Implants move wherever they want. Bending over, sternum hurts & breasts meet and tend to lift the skin.Theyre under my armpit. Laying back my sternum is blank.They reach my collar bones! I need projection, reduce the implant width -I have Sientra 4.8cm with only 4.3 projection (contributed to symmastia & malposition I bet)&switch to silicone gel(Mentor's UHP at 650cc have a 13.5cm 6.5cm)