Virtual surround varies massively depending on how its implemented. It varies from unusable to a small improvement. Certainly if the tv has fairly poor quality speakers fitted then theres absolutely no chance of it working well. Often tv speakers don't have much in the way of bass or high frequency performance so theres no chance this effect will work. Virtual surround costs almost nothing to implement. Its a feature of most audio chipsets used in tvs. If they use the Dolby name they have to pay a small license/royalty fee of a few pence but thats it.