Great service from Thomann, good invention of Zildjian, thumbs up. The L80's are really the best tool at this moment to practice your cymbal skills. And yes, I did a lot of research about 'silent drums'.
About this 20"; sorry, I'm not impressed. Why? They even sound higher then a 18" L80, which are more versatile as a crash/ride.
Yes, the 20" look good like all big cymbals, and yes, they are maybe just a bit more balanced, better for very fast and VERY HARD HITTING ride grooves. But with a good technique you can do the same with the 18".
May I suggest you to try and buy the old L80-packages, which are better because they are more versatile, and cheaper.