Giday, Al. I can't compare the two, but have recently used the SEM Color Coat on every piece of vinyl on my car and can say that it does everything it is supposed to do. Easy to use, colours over black surfaces very well and the stuff goes a surprisingly long way.
Three cans was enough to do both seats, the door side panels, the dash, the shifter and E brake boots, plus my 1/2 tonneau. I did use just a part of a can of their Vinyl Prep, pn 38243. The process was to wash the parts with soap and water, then dry.
Spray on the prep and gently wipe dry ( no scrubbing needed ). Then rinse with water, dry, then spray on the colour coat. I did about three or four light coats. You don't have to worry or be careful of streaks, just re spray where it looks a bit light.
The only caution you really need is you have to continually wipe off the spray nozzle else you'll shoot out a drip.
One last bit for you is that the colour chart on line or the top of the can is not bang on to what you will experience after you spray. This apparently is normal and in the case of the SEM product, the final colour is a fair bit lighter than predicted. I just experimented with two different cans and we chose 15483 bluebird brown.