Do ceramic bearings make a difference in motors over the standard ones??

Is a bird in the hand worth 2 in the bush?

If the bearings in the motor are perfectly fine I wouldn't replace them with ceramic looking for a performance gain but if they need to be replaced I would go with ceramics. I've got a 10.5 that's like 4 years old and the stock bearings only now are at the point of feeling less than new. At this point the rest of the motor has miles on it so personaly I will just replace the whole motor and keep it as is for a rarely used back up. $.02

The main reason to upgrade to ceramic is to gain a higher safe maximum rpm of the motor. There are other benefits too but the gains are generally too minuscule to really notice.

The rotor is usually the limiting factor. If you're already able to spin to the rotor's limit, ceramics will just get you past the rotor's rpm limit and poss failure.

If you're just looking for friction reduction with the ceramics, there's not a lot there.