I've got a couple of Tsunamis, which I like a lot.
I have one LokSound, which is in an S1 Alco switcher. I love the sound and slow motion performance. But, they did put in one feature that may be a problem for you. When the engine is idling, the decoder first spins up the "diesel" before it starts the locomotive moving. So, there is a very noticeable delay of several seconds between pressing the buttons on the throttle and seeing the locomotive start to move. This, I am assured, is actually more realistic than instant response. However, this is a switcher. If you have the same feature in a road engine, you need to make sure that all engines in the consist have the same feature, or you will never be able to get them to work together smoothly at low speeds. To my knowledge, you can't shut this feature off, either.