Okay, here's what we found out.......ridgid core is most suitable in houses or places with really strong subfloors. It doesn't like deviations or ups and downs, causing joints to open and groans and creaks. It also can be very hard to install in small places as you need to tilt the planking in order for the joints to click together.
Might I make a suggestion....glue down Flexiplank Luxury Vinyl Planking. This product does not expand or contract as it has a fibreglass core. These planks, like in the link down below, will follow ups and downs with no gaps; softer to walk on than ridgid core; far more easily repaired (hot air gun and the glue will release; pull up plank and replace with new one); cheaper and easier to install as it falls into place and cuts with an exacto knife (box cutter).
I really wish I had done my AS with this flooring.
http://xlflooring.ca/products/flexiplank/
Cheers
Sidekick Tony