the orange flo flex ones are designed for extreme articulation when offroad,but also give you a good ride on road,the yellow britpart ones are really stiff and tend to split a lotAdvantage: they don't deteriorate
Disadvantage: they're stiffer, so they limit suspension flexibility compared to rubber bushes.
Apparently someone is developing a polybush that's soft like rubber, but I don't know any more details on them or whether they're (widely) available yet.