false.
that may be true the very first time, as the synthetic does its "cleaning" but after running it a time or 2, there will be absolutetly nothing there capable of clogging the filter. this is why when you run synthetic or a synthetic blend for the first time, its recommended to change it sooner then normal
synthetic oil doesnt sludge up like conventional,
in fact it does the opposite, cleans! it also conditions seals to prevent cracking/deterioration, it has better flow properties, and it protects better. when you buy synthetic, youre getting ALOT more then just an extended oil change interval