I typically order medium from CR. I ordered medium in this. It fits perfectly. Maybe too perfectly in the top, I'll touch on that more later.
The pants are great. I'm 5'5". They're not too long or too short. They're soft and the pockets are nice. They move well, nothing pulls or pinches at weird angles. Pants are great.
The top is super soft. It fits like a glove, moves fantastically. I have full range of motion with no pulling or squeezing in odd places. However, this shirt is *HOT*. You cannot pull up the sleeves. There is no give in the fabric/design to be able to scrunch your sleeves up if you get hot. They are all the way to your wrists and that's where they're going to stay. That includes if you need to do everyday tasks like washing your hands. You cannot move these cuffs up, so they're just going to get super wet. Wet cuffs are very uncomfortable. After some finagling, I was able to roll the sleeves up twice, which helped with keeping me cool, but from how my desk ergonomics are set up, I'm finding that the 'bulge' created from doing this presses into my wrist. Not a pleasant feeling after gaming a few hours. The collar is also very high, but I was able to unbutton the three buttons just fine and that helped with trying to cool off a little. (Without the buttons undone, I wouldn't have even been able to wear this the entire night. It was so hot.)
I would like to note that I am typically a very cold person. I wear full length sleeve flannel jammies in the winter. This top had me boiling. I didn't even need my blankets fully covering me last night because of how well this keeps the heat in.
Due to the issues with the sleeves, this seems like the type of pajama set that you can't change into until you're going to bed. (Seriously, who wants wet cuffs every time you go to the bathroom). I personally prefer to change into pjs a few hours before bed, so I'm not sure how often I'm going to be wearing these.
If you are a chronically very cold person, this would likely be a great set for you. If you are not always freezing, you likely want to pass on these. They are just too hot and, because the fabric is so well fitted, give no ability to try to regulate your temperature by moving the sleeves.
Maybe they will be better when it gets down to 5 degrees Fahrenheit. Right now, it's on the 20s, so maybe it just needs to be colder.