Hi Ashish,
They actually gave you the right response the first time, if you want to take the term realtime literally.
The literal truth is, there are, literally, no realtime consumer GPS receivers on the market.
The technical truth is that the design of the GPS receiver requires that the firmware in the receiver do some computations on the information received from the satellites before declaring a position coordinate. This computation is complex and takes a measurable amount of time. The result is a delay between the time you are at a particular point on the earth and the time the receiver either logs the coordinate for that point or sends it to a PC nav program to display your position on a map.
In another thread about this subject my testing showed that the delay is typically one to five seconds between the time I pass an identifiable point (say, the centre of an intersection) and the time the vehicle icon on the map display shows me passing that point.
The second response you got is a more realistic response. For all practical purposes ... any typical use of a GPS receiver and it's data ... it's close enough to realtime to consider it so. For practical purposes.
If you had asked me, without qualifying it with a detailed description of what you intended, I would have given you the first answer. Technically, by the true definition, it's not realtime. But that shouldn't be any concern for you. As far as performance, the Qstarz are rated as good as any consumer receivers on the market. That's all that matters ... unless you have some really wierd, totally customized application that requires some incredible degree of time-based accuracy.
For things like geocoding photographs or reviewing routes travelled after the fact or doing in-vehicle navigation, these things do a great job. They are, technically, "near-realtime" devices.
Y'er welcome...
...ken...