Ok, it's an argument about which curry is the best; there's just too many. S&B is the one that's mild enough, you end up noticing many amazing subtle flavors inside. Check out the ingredients!
The japanese are the experts on "english" curry, and this is an everyday choice for them when they don't use the cubes. The cubes by the way contain lard, so sometimes the powder is the better choice if you have vegan relatives
You can dress this up with a quarter cup of coffee or some chocolate powder, to make it more like Curry House.
However, it is probably not gluten free. There's no gluten containing ingredients, but the potential for cross contamination in the grinding machine is there, and S&B has yet to specify on their web page.