First off, I was wondering what you consider a med. Rat. I'm a scale junkie, so I weigh and record everything that goes in. Not necessary, but I just like to do it to keep records of everything.
I think generally as you mentioned there are two trains of thought on feeding size.
Some like to feed smaller items more frequently; while others prefer to feed larger items less frequently.
I like the first method. In snakes of about that length (depending on girth of course) I feed rats of about 100-120 grams every four or five days, with good heat and exercise in between.
I can’t say there is greater benefit from either method, but this is the method I prefer. Movements are regular, and the snake doesn’t sleep for three days after a meal. I also have had good results from this method as far as size and weight gains in my snakes.
Again, I don’t think there is any data to say one method is better than the other, but that is what works for me.
TomChambers