As a new empty nester, I have been bequeathed another empty room to build a second layout. Although I love my TIU and remote, I figured I'd pick up the new WTIU for this new layout. Like H1000 said, I can still tether a remote to it, which for me works just fine, since i usually operate my bedroom sized layouts while sitting in front of a control panel (I don't ever walk around). I can see the benefits of each form of control (app or handheld) and am willing to give the app a try. Who knows, I may like it better. Surprisingly, a couple of die hard DCS guys i know now tell me they love the app and now rarely use the handheld (their grand kids love it and they don't care if the grandkids drop the phone like they did with the handhelds). If those old geezers can get with the times, I figured maybe it will be ok for me.
I'm also planning on buying one extra handheld to tether with the WTIU if I ultimately don't like the app.