I also owned the Focus S prior to my Titan (Nov 7th - Nov 28th), and I think that you should play with one in person before you do this. The build quality of the Titan is far superior IMO. It feels much better in my hand. I also have had numerous conversations on my Titan and nobody has asked me to repeat myself or made any comments to indicate that they are having trouble hearing me. Perhaps you should just swap it out for another?
The only issue that might lead me back to the Focus S is the data speed issue. I never checked my speed on the Focus S, but it did seem speedier than it is on the Titan. Of course, it could just be because I have seen the comments about Titan data throttling.