That depends on what needs to be done with the data.
Do you need to search for or sort these these “meeting notes”? Do you need to list them in any way other than all of them for whatever they are associated with? Is there a need to see a single meeting note? If the answer is yes to any of these then you want to use a CPT.
Another thing to consider is the admin performance. There comes a time when there are so many items it the repeater that it will eventually cause updating to time out while display will not be affected. Repeaters do not scale well. If there could be hundreds of rows in a repeater then this is another reason to use a CPT rather than a repeater.
