I did a trust with him a few years ago. It is just my wife and I on it but, there will not be any issues having your daughter and son in law.
Since I am not near him, we set up a phone call and he asked me questions that I answered. Based on that, he setup the trust and emailed it to me in PDF format. All I had to do was notarize the appropriate pages and I was good to go.
There have been some changes to the NFA, most notability 41F, and he has adjusted my trust accordingly. When I had my trust set up John was doing a Schedule A that listed the individual NFA items so I would contact him with the info on the new NFA items I had acquired and he would update the schedule for me. He has since gone to a Schedule A statement page were it basically says anything with a stamp is in the trust so there is no need to keep updating it. John also had a phone call with me around 8pm one night and walked me through submitting my eForm 1, this was shortly after setting the trust up.
Overall I have been very happy with his services, support and turn around times.