either one is good...

the polygon would be a better value for money but then you are buying a bata shoe

the trek on the other hand is giving you lesser for your money but you are buying a nike shoe...

nike or bata, your decision...one is going to suck on the frame possibly, the other is going to suck on components possibly when you learn that you want better components...

there is also no such thing as lifetime warranty... lifetime warranty means that they will cover it as long as they are in production and there is stock for replacements... and only for manufacturer defects not user negligence or crashes...
it's for a peace of mind at the end of the day

point in case...
bata vs nike
proton vs honda

the cheaper ones can always have better offerings than the superior brand, but people still opt for the latter for the confidence and peace of mind...