The H9000 features an exact port of the H9 Spring algorithm. The Spring plug-in is also a port of the H9 algorithm, but we added a selectable tank size and pre/post option for the tremolo circuit that is only featured in the plug-in version. We’d like to add the plug-in version of Spring to the H9000 at some point but there is no set date for this.
Besides those differences, you should be able to get the same sounds using the H9000 as the plug-in when using the small tank and post reverb tremolo settings.