Physically, each pleo is unique as they are painted (air-brushed) by hand. But each pleo is programmed the same. But just because they are running the same program, does not mean they are not unique. Millions of computers run the same operating system. So they all have the same basic functionality, and they all respond to the same basic commands in the same way. And they all start out identical the first time they are turned on. But from that very first time a PC is turned on, no two are exactly alike. Based on how the person uses the machine; how he configures it, how he customizes the settings, icons, desktop, backgrounds, colors, themes, what software he loads . . . In the same manner, pleos have settings that are adjusted but the pleo's environment, how we treat it, how we interact with it, etc. Thus, even though all our pleos have the same OS, and all start out exactly the same, from the moment we turn it on, we start molding the "personality" a little differently, so each pleo is in fact, unique in it's programming.
Sure, they all respond the same way when we rub under the chin, but some pleos react differently to being picked up, some pleos explore more than others, some pleos, and some pleos eat, sleep, get sick, or cry more than others. It's because although the program is the same, the values of the variables stored in the setting files of each pleo are not the same.
SO, yes, no two pleos are the same.