  We study observational constraints on the non-metricity $f(Q)$-gravity which
reproduces an exact $\Lambda$CDM background expansion history while modifying
the evolution of linear perturbations. To this purpose we use Cosmic Microwave
Background (CMB) radiation, baryonic acoustic oscillations (BAO),
redshift-space distortions (RSD), supernovae type Ia (SNIa), galaxy clustering
(GC) and weak gravitational lensing (WL) measurements. We set stringent
constraints on the parameter of the model controlling the modifications to the
gravitational interaction at linear perturbation level. We find the model to be
statistically preferred by data over the $\Lambda$CDM according to the $\chi^2$
and deviance information criterion statistics for the combination with CMB,
BAO, RSD and SNIa. This is mostly associated to a better fit to the low-$\ell$
tail of CMB temperature anisotropies.
