I've heard many a soundbar. Some expensive, some cheap. Yes, the more money spent the better definition or clarity of dialogue and (slightly) deeper bass than the TV speaker. No matter what there's no getting around the physics of location of the sound source. Perhaps with some form of Olympic level gymnastics in room design acoustics, design of the soundbar and strategic placement you might achieve a minimum level of surround effects. It's just far easier and more economical to just setup a real surround array of separate speakers.