I'll tell you what I know. The newer CPE-2 plus does have a different motor than the old model CPE-2, probably stronger. The old model CPE-2 does not have the thermal cutout safety feature. This just means never turn the older model on unless the resevoir is filled with water. Will the older model drive a tank with four rolls? Yes.(posted 8303 days ago)I would hesitate to buy an older model, unless you know that the original owner didn't use it that much and it has a lot of wear left in it.
Call Jobo, their technical support can answer a lot of your questions. If you know the serial number of the machine your thinking of buying, they can tell you more about it.
Jobo 1-800-525-2821