A while back I reported a problem (on a 120g disc) in which I could hear the beginning of Side A audibly imprinted through the disc while listening to the start of side B. I'd never previously heard a phenomenon like this. It certainly wasn't the type of thing that could have been caused by print-through on a tape because you tend to hear the end of the other recording rather than the beginning. (Even if it was on the same tape). You wonder whether such an effect could have ever happened with a 180g.
Unfortunately 180g LPs can have other more serious problems (non-fill being possibly the worst - and undeniably worse than the one mentioned above).
Having read all the arguments I think flatness of the LP is possibly the most important recommendation. Good mastering should be automatic regardless of the thickness.