We bought the Disney ones on our trip last month and my 5 year old son ripped his within 1 hour of wearing it, they did replace it for free. All I had to do was show them the rip and point at my kid. They are much thicker than the cheap ones, my son is just hard on clothes and apparently ponchos. My husband also tore his later that day, I think because he's 6'7" and it fits him like a shirt more than a poncho. Again, Disney replaced for free after asking to see the rip.
I think I'm also someone who would do the cheap poncho/Disney poncho combo. Because the cheap ponchos take up much less space in a bag and if it's not going to be a heavy rain day then those would be easier to carry.