  We reanalyse the anisotropic galaxy clustering measurement from the Baryon
Oscillation Spectroscopic Survey (BOSS), demonstrating that using the full
shape information provides cosmological constraints that are comparable to
other low-redshift probes. We find $\Omega_\mathrm{m} =
0.317^{+0.015}_{-0.019}$, $\sigma_8 = 0.710\pm 0.049$, and $h = 0.704\pm 0.024$
for flat $\Lambda$CDM cosmologies using uninformative priors on
$\Omega_\mathrm{c}h^2$, $100\theta_\mathrm{MC}$, $\ln 10^{10} A_{s}$, and
$n_{s}$, and a prior on $\Omega_\mathrm{b}h^2$ that is much wider than current
constraints. We quantify the agreement between the Planck 2018 constraints from
the cosmic microwave background and BOSS, finding the two data sets to be
consistent within a flat $\Lambda$CDM cosmology using the Bayes factor as well
as the prior-insensitive suspiciousness statistic. Combining two low-redshift
probes, we jointly analyse the clustering of BOSS galaxies with weak lensing
measurements from the Kilo-Degree Survey (KV450). The combination of BOSS and
KV450 improves the measurement by up to 45%, constraining $\sigma_8 = 0.702\pm
0.029$ and $S_8 = \sigma_8\sqrt{\Omega_\mathrm{m}/0.3} = 0.728\pm 0.026$. Over
the full 5D parameter space, the odds in favour of single cosmology describing
galaxy clustering, lensing, and the cosmic microwave background are $7\pm2$.
The suspiciousness statistic signals a $2.1\pm0.3\sigma$ tension between the
combined low-redshift probes and measurements from the cosmic microwave
background.
