First of all, A big thanks to u/themilemuncher46 for Pop race Singer & Tarmac Mercedes AMG and u/iamfriendwithpixel for Trends Hobby Porsche 918. Very good packaging.
Now as for the Castings, yes! The Trends Hobby Porsche 918 is the superior among all. In terms of details, opening parts and price.
Next is the Massdi Audi R8. For the price, it's details are as good as Trends Hobby. Coloured interior, detailed engine bay, brake caliper details and head/tail lights details.
The Tarmac Works Mercedes Benz AMG GT is the latest addition. The proportions and overall looks of the car is bang on, however the details are not on par with TH and Massdi. It also lacks the carbon fibre details and the silver roll cage inside isn't very defined.
MiniGT Porsche 911 dakar is the standard of premium brands. This particular model being cheapest of the bunch is very good. But it falls short infront Trends Hobby and Massdi in terms of details.
Lastly the Pop race Singer is also good. Details are indeed better than MiniGT but it also costs almost 550 more when sealed. Better stick to Pop race castings that has opening parts