Thanks for the replies everyone. Prior threads also mention that string weights could be different but the jury is still out on those.
You paid to have the frames matched without strings? Or did you ask for 2 frames that are close to what you want without strings? There's a big difference if you asked for option 2 vs option 1. Close is not the same as matched. Note that you cannot ask for matched frames with strings because when the retailer goes thru their stock, they will not string up the frames with your chosen string, then match them. Now that this is out in the open, are the balance and SW close? Which is more important to you?
Your second question is related to mass of strings. They will be different because your crosses are not made from the same material. 4 grams is a little big, but if different gauges are also involved, is possible.
They came from the big website in TX. I paid to have them matched in weight and SW. They say they were matched but they do not keep records of what the weights were. My guess is that they did it with the plastic and cards on. I don't know what the SW or balance is as I have not tested it yet.
I do have full set weights on the following strings:
Pro Red Code Wax 17 - 21 grams
Babolat Origin 17 - 17 grams (Note that this is 17 gauge and not 16)
Lux ALU Power Soft 16L - 20 grams
There is a 1 gram difference between the Red Code and ALU but once you factor in half sets in the crosses it's 1/2 a gram or less difference. That means that the Origin and NXT would need to be 3.5 grams difference for the racquets to be the same.
It would be nice if they were exactly the same so when I do decide on what strings I like best, they will both be the same. I don't expect the racquets to match while they have different string and I realize this weight difference is about as much as a dampener. It seems like sending them back may be overkill and I should just modify them when the day comes.