Well the only time I ever did it I was lucky to survive the encounter.
I know that sounds scarey but hey there are some bad people out there. I even chatted to this guy and what I thought was his wife/sub for three months online before going to meet them. It was all a scam and turned into a living hell.
He is coming to meet you thats good. Home turf advantage. I highly reccomend that you have a responsible third party standing by to call the police with your location if you don't contact them by a specified time in person. It is a good idea to have this arrangement for some time well into the relationship in my opinion. My attacker/abductors didn't act funny until I had been with them for 2 whole weeks and then it was too late to get away.
It is also a good idea to not go anywhere alone with him at first, at the very least have him meet any friends that you might have available. The more people that know you are meeting and where the better.
Remember no matter how much you may think you trust a new dominant from online you don't really know him in real life yet.
That kind of trust can only be earned over time with actions.
Saftey first~Kink second.
I will pray that all goes well for you and that your experience will be far different from mine.
In fact I wish you both nothing but the best.