I approached my purchase same as you not necessarily looking for that immersive surround sound experience but after being disappointed with the 103, I didn't see how you can separate the two, which is why we started looking at the 1400.
Originally My wife and I purchased the 103 then after a week we exchanged it for the 1400. We bought it thru Amazon in late August at that time the price difference was/is currently $100 and that's about where the similarities end.
We purchased the soundbar to go with our Samsung TV, Directv Genie 44 and Sony Bdp-5200 bluray player., in our 12x12 bedroom. We found the 103 a disappointment when compared to the Zepplin Air it replaced. For both soundbars the individual remote controls handle the volume seamlessly. (Samsung's native TV sound is disabled in the firmware. The only issue I've has with remotes is off/on and input changing on occasion. If the remote doesn't turn the sound off it will turn off automatically).
The underlying technology they each employ is completely different, the YSP line uses Sound projection acoustics that can be tweaked, while the YAS utilizes a speaker in a box. We using it in a 12x12 bedroom and find the 1400 vastly improved over the 103 in every respect. I'm deaf on one side and we chose the yamaha line primarily for clear voice function. In this regard the 1400 is noticeably more successful more then the 103. Television and DVD movie music / surround sound is much livelier and both my wife and I consider the 100 dollars very well spent. Between the clear voice and the univolume we rarely adjust the 1400 unless we change the source, and not always then
For the room you describe would urge you to read reviews for the 1400, some people with open rooms have been disappointed. If it was me, if I didn't choose the 1400 I would look further into the YSP line or better. My opinion is the YAS-103 is nothing more then a loudspeaker with a couple of features, whereas the 1400 is entry level theater sound sound system with some extra bonus features, ie clear voice.I haven't yet had the 1400 cranked all the way up - my wife complains about the floor vibrating.
The ios/android apps do a wonderful of full control over either bar, in fact I got a Directv android app that's totally seamless.
I tried to post a manual for you but the board wouldn't let me. The manual is available online however.
Last edited by Dohickus; 10-09-2014 at 09:43 PM.