A version 4 Loksound will totally blow you away.
If you thought Tsunami's had good engine sounds, your really in for a treat with a Loksound.
My first ESU was an Intermountain SD40-2 with factory fitted ESU Loksound and Ive just got (well about 3 months ago now) an Atlas S2 switcher, again with factory fitted ESU Loksound. It is just fantastic and probably the most realistic model engine sound Ive ever heard and believe me, Ive heard a few!
I also read a lot of how an ESU decoder controls the motor and again it impresses in that aspect as well.
There is a delay of movement when speed step 1 is selected, the engine note rises before the model starts to move just like the real thing, they are simply gorgeous!!
All of the above was seen 'out of the box' without messing with any CV's except for the address!
Would I change out about a dozen Tsunami's for Loksound decoders?
If I could afford to, yes, I'd do it tomorrow.
Don't take much notice of video's on these sound decoders on youtube and the like as they just don't do them justice, you have to be there to appreciate how good they sound.