Notes:
SZ surveys are ideal to measure the cluster redshift distribution, and thereby constrain cosmological model parameters. It is especially important to detect enough clusters at higher redshifts to measure, eg. Omega_Lambda.
Note that the amplitude of the cluster number counts is a strong function of the normalization of the matter power spectrum, sigma_8^5.
The SZ power spectrum C_l ~ sigma_8^7 (Omega_b h)^2