After the pions and kaons, the rho mesons are the lightest strongly interacting particle, with a mass of 775.45±0.04 MeV for all three states.
The principal decay route of the rho mesons is to a pair of pions with a branching rate of 99.9%.
[2] The rho mesons can be interpreted[3] as a bound state of a quark and an anti-quark and is an excited version of the pion.
This mass difference between the pions and rho mesons is attributed to a large hyperfine interaction between the quark and anti-quark.
The main objection with the De Rujula–Georgi–Glashow description is that it attributes the lightness of the pions as an accident rather than a result of chiral symmetry breaking.