Tandems of the forum

+1 for drum on a friction shifter.

We have experience with Vs+drum, Vs+disc, and discs only, and never had any serious issues apart from consumables wear on hilly areas. Any configuration can be set up to stop you safely as long as everything is put together properly.

However, in terms of feel I'd say that drag brakes are a noticeable improvement, I feel safer when I'm able to add resistance so the bike doesn't build too much momentum. To be able to do that without overheating rims or discs is a neat solution, so I'd go with Arai too.