yes you will notice one hell of a difference going from a proper 5.1 (or 7.1) setup than you currently have, you will be going from a powerfull amp with proper Dolby TrueHD/ DTS Master audio decoding to a soundbar, most of which cannot decode these formats, I have heard a couple of these "soundbars" at an audio show a few years ago and they were terrible, no surround sound separation to speak of, just a load of noise coming from the front, in my opinion they were developed because most if not all audio from built in speakers on flat screen tv's was found to be useless.
sorry for my previous reply, but I am passionate for proper surround setups whatever the number of speakers, lengths of cable etc required, (if ever my 6 numbers come up theres a company that has brought out a Dolby Atmos/ DTS X pre-amp capable of outputing up to 32 speakers and 10 subwoofers).
*music2*