I bought these strings because Nadal used them and I found out they were great. They lacked a little feel but the power and spin were great. They have decent control and durability is not an issue
This string provided plenty of pop but I felt that it lacked any feel and was harsh to my aging arm.
With so many good choices out there, this product stands out. If the price does not bother you, go for it. RPM plays well with very good spin, as advertised.