Just like most of you i wanted to use the pi5 but was forced to use the pi4b. Having spent a lot of time developing software for the pi5 and pi4b, using a.i. functions, i can assure you that the pidog works fine with either except for battery life. It isn’t great with the 4 and rather pointless for the 5 which drains the useable charge quickly. There is no noticeable difference in dogspeed between pi’s, even with the bit of a.i. running. The older version servos let the product down. If i was to buy now, i would choose the pi5 version for the better servos and use the pi4 for the better run time.