It is easy to make them fit.
I like the echo attachments so much better made.
My wife still likes the ryobi power head.
The cub cadet 4 stroke is to heavy for her bit is full of power.
It's an art to keep the oem angle and pitch. Without taking to much medal off you do one side on each section then start and move the blade to make the other parts accessible. Easiest way to keep them Sharp after is lube the bar with wd40 often even while pruning