You can get the er9 for less. You can get a crankset for much less. At this price you're in Chinese carbon crankset territory, which is hundreds of grams lighter than Shimano. A 50 euro cassette is an ultra light which is dura ace level weight. You can get 2 rotors for 10 bucks, that's what I use, as approved by peak torque. AliExpress in Europe includes VAT. Also worth noting that it can be tough to get the exact spec you want from Shimano, across crank arms, chainrings and cassette sizes.
Well you can also get 105 di2 under 1000eur. I just made a high level comparison.
It's worth what is worth and each person is free to take their own decisions. And it's good that it's like that... Else if we all liked yellow what would be of blue.
Ali doesn't include vat above 150euro so if you get the er9 you don't pay vat (unless you get them under 150 euro on ali, and for that I would also try it ahah). As for the weight approach it's an argument maybe for some people.
I actually think the biggest value of these Chinese electronic groupsets is on the flexibility of adapting it to current system being it 10, 11, 12 speed or other.
I prefer an iPhone to a Xiaomi top specs. Even if the iPhone is 14 and the xiaomi was launched yesterday.
Anyway happy to hear reports and to follow the topic.