All depend, if you want only mufflers or a system with a cat by-pass(The triumph cat by-pass is not well designed).
Maddogs are mufflers only.
They deliver a nice sound (I've only heard with the box +catalyst) not too loud.
The look is not the same than the stock one.
Thunderbike as designed a complete exhaust system with their specific and well designed cat by-pass and 2 or 3 mufflers option with excellent results.
The 3 mufflers look is about the same than the stock look.
Thunderbike by-pass :
Staintune has also designed an excellent by-pass, but it's only compatible with their mufflers (strange look)
Staintune by-pass :