H pipe vs X pipe vs no pipe

Ok so I need to order some exhaust for the car...

Summit has their own brand dual kit with mufflers for $209, however I think it is a basic dual kit with no connector pipe

For $290 there is another brand with an x pipe and mufflers

I haven't looked in the h-pipe systems


So school me on pipes..... is the X the best? How much of a loss is there with no connection between sides?

What will the x pipe do to my exhaust sound?

Thanks