All I know is metal beats plastic. I guess in less you care about the noise of stones hitting it.
A piece of metal is only as good as the points it's mounted to. If you're referring to the ECS tray, I'll take a rigid plastic mounted to rigid points over metal slid onto flimsy plastic. And their upgrade, based on GolfDave's thread actually, isn't designed to fit an R.
And besides not everyone has a 400.00 dollar bill including shipping to throw at a skid tray.As far as Ali Express,I just installed a set of dyna blinkers for my mirror signals I bought from them for 88.00 USD and they are very good quality.
I spent $77 for a brand new skid plate (the one golfdave put in his DIY), not including mounting hardware. So, probably around $100 total in parts. You had the money, you just chose to prioritize blinker aesthetics over protecting your oil pan. I'm not saying there's anything wrong with that, but don't use the excuse of money as your reason for not getting a skid plate. If you can't wait for a good deal, and have to buy today, you can still find them for ~$200. Still much less than $400.
There's a few shortcomings on the MQB platform, the fact it has a cheap aero tray and a plastic oil pan is one of them. A lot of people complain about VW being cheap with the oil pan, but they themselves can't spend the $200 to get a metal oil pan and true skid plate.