To be honest it was that the DTW came in the external configuration I wanted. As it was a backup/loaner gun, I didn't want to fart around with getting a nice rail system on it.
For anyone interested, I did caliper the body pins and the DTW ones are about 0.3 mm smaller than the Systema so the DTW lower will take a Systema upper but you cannot put a DTW upper on a Systema lower without boring out the holes on the upper a bit. I have not done this but I'm told it works.
Additionally, I had a pinion blow on my PTW and I put the G&D motor and pinion in to replace it and it's performin