I did recently do this on my Evo runnin MikGs Sense 2.1/3.0 rom ver. 2.20. I enabled EVRCB,then switched my home setting to EVRCB. I cant tell much of an in-call voice quality increase,bcuz it was damn good before. However i can tell a big difference in the in-call voice volume. Before,on EVRC,i had the call volume almost all the way up. After switching to EVRCB the in-call volume sounds noticeably louder.So much that i now only hav the volume set about one quarter of the way up. Everythin else seems the same,but ive only been using EVRCB for about a week so far. Ill leave it on,unless i notice.any negative effects,but so far call quality is great,but it seemed.great before too,just not as loud. I dont even know if my city is EVRCB enabled? But it doe make the incall volume louder at much lower settings.For wat thats worth. I havnt had any droppd calls,static,nothin bad yet.Ill pos t if do. I hav a rootd device & i used the msl reader app,or watevr its called,from the android marketplace to get my msl for my evo.