And I'm just letting you know, that adapter had nothing to do with providing you the option of getting 1080p. That option was provided by using a HDMI port instead of the VGA port on that particular TV.
While different cables do have varying capabilities, what you are experiencing connecting to your TV has to do with the resolution capability of the ports you are connecting to, not the adapter, nor the cable.
You can open up the User Guide for your TV, and if it's any of the major manufacturers it will have a section providing the resolutions it's VGA port is capable of. Many TV's do not provide a full range of resolutions via their VGA port like you would see on a computer monitor. Just one of those places where they scrimp to save another 20 cents.
Whatever your particular TV is capable of via VGA, would have absolutely no bearing on another brand or even within the same brand on different year models they changed so much. Many widescreen TV's still only provide a 4:3 aspect ratio available via their VGA port instead of 16:9.
The resolutions available from a monitor/TV are transmitted to the device via what is called EDID.
You can read about it in the Wiki
here.