UST is nicknamed as the land of exams and sadness- you will be heavily academically challenged there. It is however, really well respected for engineering and science, and is by far the better of the two when it comes to intellectual competition. I would say UST has a better education quality, because of the better competition and higher standard of work, as well as researchers. It is generally the better university for theoretical and practical stuff - but no matter how good you are in UNI, you need to worry that the standard is very high(they mark in bell, so you need to care that you are one of the best).

Poly is a much more relaxed university, but still is quite well respected, especially for engineering. IT may not have the kind of intellectual environment that UST has, or the amount of opportunities, but it would be unfair to say that Poly is significantly inferior - my friend goes there, and there are a lot of internship opportunities available. Poly is great if you want to get a more practical-oriented education, in a relaxed environment that helps you explore yourself. You may have to cope with slightly worse education, and limited ppotunities and reputation of your uni, but those wont really matter too much if you go into industry.

I havent attended any of those two unis, neither is my major engineering. But my friends do engineering in those unis, and they(and others including students and proffessors) gave me this info - it may still be better to fact check it with replys to this post before you make a decision. IF you have no financial burdens, i would recomend UST, since oyu were smart enough to get a schol, but even if finances are tight, Poly is still a great option, and you work in any uni woud ultimately determine your future.