The Mazdatrix kit appears to use 19 row oil coolers, ours use 25 row (much more expensive). I don't know much about the Mazdatrix kit, but from the pictures it looks like the lines are not pre-made, and you have to make your own brackets to mount the coolers. Our kit comes with pre-made lines to the correct sizes, and brackets to mount the coolers and thermostat, which will save a TON of time during install.
Personally I like the standard line better then stainless, they look OEM in my opinion. Also the standard lines are a little easier to work with. The only time you would not be able to use the standard line was if you were running a dry-sump oil system. It comes down to personal preference, some people like the stainless lines better. I don't like to give a biased opinion, but our kit is complete and ready to install. The Mazdatrix kit looks like it's more of a DIY kit.
-Dan