MRT is around 500m, i observe one of the agent video they use 4-5min walking. but if follow future covered walkway path, i believe the time taken will be much longer cause you cant go with shortcut.(normal slowly walk for 500m maybe around 10min?)

Agree, 500m is walkable but not comfortably walkable. For me below 200m distance is best, can reach before we start to sweat.

I once debated someone who said 500m-1km is optimal walking distance 
https://forum.lowyat.net/index.php?showtopi...ost&p=104606400

500m actually is considered quite far distance. But its depend on how they work with the covered walkway. Do take note the walkway not only served this project, even Serina, 8th Stellar, nearby residence will be using it. So, if it's not a proper one, you will faced problem such as wet floor, unhygiene condition, wandering people and rain water splashing. And, if the walkway is narrow and not properly lighted up, safety might be an issue also.

in conclude, when the walking become continuous, boring, and make you sweat, it's consider FAR....