For me the tank sounds are as important as the paint. I want to have unique sounds, made by me. That's one of the reasons I love so much the ASP board: I can play hundreds of diferent sounds, commander voices, explosions, radio orders, music... Thats the most funny part for me.
I dont think we will see something like that in the near future for HL or taigen... But custumizable engine sounds and a couple of extra sounds like the Ibus would be great if they are cheap enough.
And yeah 1/4 of track recoil, please. Lol.