After doing some research and listening to what the good people here have had to say I went and made my first CaDA purchase a few weeks ago.
For anyone wondering about the CaDA Alfa Romeo F1 and the Lego McLaren F1 counterpart I thought I'd do a bit of a comparison. I don't know if anyone is interested or even cares but i'll do it anyway. I'm from Australia so anyone in my region wondering I bought it about 2 and a half weeks ago. It took about 5 days to change from purchased to sent but from there shipping was very fast.
CaDA Alfa Romeo F1 vs Lego McLaren F1
Price - I paid $210 delivered for the Alfa vs $250 for the McLaren
Presentation - The Alfa is presented like the Lego 1:8 supercars vs the McLaren is presented like a standard set. The materials with which the box is made of look/feel a little lower quality to that of Lego but that's neither here nor there when you look at the overall presentation
Parts - I'll start by saying I'm still early in the build but, CaDA seem to manufacturing a lot more unique parts for their sets rather than Lego "use what we have" approach. Depending on where you stand will determine how you feel about that. This could be due to manufacturing costs giving them more freedom to do so or CaDA continuing to build inventory since they're not at the same level as Lego. However the wheels and slicks for the Alfa are by far superior to that of the McLaren (Lego take note). So far the rest of the parts look to be of a good quality, and the pins give a satisfying click when pressed into the bricks, beams, panels etc. The axles have a feeling like they're not quite as good a quality as Lego but time will tell. With the Alfa being a display piece more than anything this may be inconsequential (this may be an issue with the power functions sets), time will tell. Also looks like a lot less colour vomit compared to Lego
Stickers - I'm not up to having to apply any yet but again this will be something that you won't find out until 6-12 months into the future. I'm a little worried about the clear stickers compared to the coloured stickers of Lego. I feel like any imperfections will be very noticeable. I think a lot of care will need to be taken during application (someone with more experience may be able to elaborate). Little disappointed that there is no option to sticker it as Valtarri Bottas but being a Chinese company with a Chinese driver I can understand.
Summary - Seems like a very good product and I'll have no issue with buying from them again. For anyone looking for a supercheap alternative to Lego, this is not the product you're looking for, and that's a good thing.
Finally - It's not Lego :) Also if I knew how to attach decent photos I would have added a couple