Using Flex Track With Unitrack
Thomas Tuerke has a great tutorial on his site about using Flex-track on his T-Trak module. I think one of the best reasons for this approach is it eliminates any joins between different types of track on the module. With flextrack coming in 3 foot segments, you can do up to a triple using a single piece of track. (assume not much flexing is happening on your triple LOL)
Thomas is using flextrack on his yard modules, but I think this method would also shine on the T-TRAK-N S-Transition Double modules.