I agree with j garcia - sounds like whatever you've had before wasn't properly calibrated and/or arranged. Every system is going to have a sweet spot, it's inevitable, but shouldn't equate to sounding lousy anywhere outside that spot. Sound bars, IMHO, were invented strictly for wives, and husbands who could not get them to agree to a multichannel speaker system in their living rooms.
The ones I've heard don't sound terrible, but they're never going to give you a true surround sound experience like a full 5.1 or 7.1 setup will. To put it in other words, they are the in-between option between using TV speakers (yuck), and a full surround sound system, not a replacement for a surround sound system.