Despite a flurry of advanced TV features such as connectivity, LED backlights and of course 3D, the main reasons why people decide to buy a new TV appear to be the same as they ever were.

Specifically, suggests the DisplaySearch Global TV Replacement Study, it still remains the desire to have a newer, bigger and better performing TV.

The most crushing disappointment revealed in the survey is the failure of 3D to gain traction. In what will be a huge blow to manufacturers who are ramping up the production of 3D sets in the hope that reduced unit costs spark interest, the survey actually suggests that 3D capability is one of the weakest drivers of new TV replacements.

DisplaySearch notes that few new TV features have attracted as much attention in the last year as 3D and although it accepts that although 3D TV shipments showed strong growth in 2010, it says that the study results indicate that consumers aren’t looking to make a new TV upgrade just to get 3D.

On a brighter note it does add that 3D is a more important criterion for consumers who are already looking to purchase a new set. That said, the analyst believes that the lack of broadly available 3D content is making 3D a future-proof feature, but not a main reason to upgrade in the first place.

Connected TVs have shown much more promise than 3D to date and the survey accepts that on paper upgrading a TV to gain internet connectivity may seem like a strong draw. In reality, marketplace confusion and lack of embedded wireless connectivity have says DisplaySearch, meant that potential consumers view connectivity as a nice to have and not a primary reason to upgrade a TV.

Even though in the main LED was a below average driver of new TV replacements, it ranked stronger than internet connectivity and 3D in most cases. Yet the study showed that only in urban China and Russia was there above-average incidence of LED being a reason to upgrade an existing TV.

“While it is valuable to know how often people are upgrading or adding new TVs to the home, it’s also important to understand why,” commented Paul Gagnon, Director of North America TV Research at DisplaySearch. “Some of the findings from this study show that newer features are not yet strong drivers of new TV purchases compared to fundamentals like trading up in size or getting a flat panel TV.”