Yes. Not worth it IMHO. I prefer the MSFS weatherengine that works globally instead of a very limited weather only around my plane. My experience with REX in MSFS was not really good at all.
It switches the weather very drastically based on the METAR of a near airport. So you will have completely blue skies when there should be clouds in front of you already visible.
MSFS weather does that better, and it will get more updates very soon to have better METAR accuracy.
Honestly, i would save the money. You have the better option already for free in the sim.