Aftermarket mounts will use like one rubber compound on everything they make and it will be hard as rock. Factory will often use different rubber compounds based on what engineering has shown to be the proper amount of damping for particular engine/chassis combinations. On the hydraulic mounts the aftermarket will be made very much shoddier with some new ones coming apart in weeks or days...............
Oh, and a lifetime warranty on those particular parts really means absolutely nothing, they are made so cheaply they actually plan on you coming back to get replacements which will fare no better. BTDT several times.