This one has been very reliable. Smooth starts and stops (similar to my 2.0 version). Ramps up and down well. Ran it a lot to make sure it was working. Same type of horn (rapid pulse) and bell. Stiff couplers - same height. Same excellent announcements. No need to wire it in series.
In terms of a further review I am not sure whether the replacement is a 3.0 or 3.5 since it is a used one. Either way it matches the other reviews of both.
Thanks for all the suggestions.
John