I've been to the Ben Thanh restaurant in south London a few times and generally have been very happy there . . .
BUT . . .
You knew there was going to be a but didn't you . . .
I hate tin teapots. The decor is okay. The service is okay. Most of the dishes I have tried are okay. Not crazy about their pad thai.
So my final opinion is that it is a good restaurant, just not a great one. You will find it quite satisfactory, just not exceptional.