In the end save your money for a more practical bike. If you have a bike with tourney do not upgrade it beyond basic safety parts to keep it running safely enough till you can get the right bike for your riding. While yes these derailleurs will be a slight improvement the rest of the system is tourney and is really for that short use starter bike or something that gets ridden infrequently due to not being able to ride more. Ride the bike, enjoy the bike, replace the minimal amount of stuff and save that money towards the bike you want or at least a bike that makes more sense for your riding. You will be much happier in the end.