It's not a science, but one difference is the very positive review for 'Common One' by Van Morrison on here - I went and checked the LP out after and loved it.
ditto (except i only keep that rec for the astounding 15 min closing track) ... i mean to check that PSB b-side flashbackcaruso reviewed too
if i had the time + energy, i'd post reviews of Ke$ha's "sleazy" single and "HPSCHD" by john cage ...