Cotton vs Poly - a myth?

[Dalronix]

Oh no, I hear you're all saying - not another topic about the pros and cons of cotton thread versus poly thread.

I'm new to quilting (started in July) and without knowing too much started using polyester thread at the beginning because of its price in Australia - $2.49 for 1000 metres (in yards it's close enough to 1000).

I haven't used Gutermann 800 metre cotton reels (the only cotton brand I've found) because they are around $14 - $16. Unfortunately I haven't been able to find any cotton similar to Connecting Threads 1200 yard reels for $2.95 (Connecting Threads won't sell to non-US residents). In other cotton thread is expensive.

Anyway, this cotton vs polyester dilemma has caused me a lot of angst because as a retired person I have to keep costs down and quilting can become/is a quite expensive hobby.

I have made two quilts - one lap and one queen - and a set of placemats (8) with matching tablerunner all using polyester thread. Now I've learnt more about quilting on here, in books, on YouTube, I've been worrying that my efforts so far will fail about because 'poly thread tears cotton fabric because the thread is too strong'.

Well, this morning I came across the following video from Superior Threads in which the claim is made that 'cotton is better' is one of those myths that get started and eventually become the 'truth'.

"Thread Therapy with Dr. Bob" Cotton & Polyester pt. 1 - YouTube

So for those who've lasted this long, has anyone actually seen a quilt rip or tear, or whatever's supposed to happen, because it was pieced using polyester thread?