I use "new/baby" reds cut into bite size pieces & boil until tender
(but not mushy).
Since I make my "egg" potato salad I cook my eggs a day earlier
and let them cool in a bowl of ice water in the fridge (I TRY to use
7-10 day old eggs as they peel much easier for me).
For me I use Miracle Whip Salad Dressing (not mayo), and standard
yellow mustard, along with red onion.