Hahahha, just a bit to share only bro. The Primacy 3ST I have got it replaced on my Camry before Raya, was done under to the Raya promotion, RM500 per piece, 215/50R17, nitrogen gas, balancing and alignment plus RM30 petrol voucher. Since the replacement, i had traveled about 700 km, from city drive to to coaster road, but still relatively new, can't tell much about it. However, my experience with 3ST can be considered as so far so good. In term of gripping, much better than Primacy LC. Better smoothness and quietness but rolling resistance, i think it is just normal as on the afternoon, i can feel the rolling resistance quite significantly, especially under the humid and hot afternoon.
I am not sure what type of expectation you would want for your car. Like me, caz i always travel long distance and i always put comfort and smoothness as priority, so 3ST will be good enough for me. But if you opted for performance and handling, may be PS3 will be much suitable for you if comfort isn't your priority. But this doesn't mean PS3 is not quiet or smooth, just their comfort, quiet and smoothness are at the normal level. I tried PS3 on vios before, i feel grippy and handling; better cornering and performance but it was quite bouncy and noisy. Well, nothing wrong with PS3, just individual preferences.