Well, I subbed to CDA, downloaded a few seups for this weeks Low Fuel Motorsports track (Spa) and spent the day yesterday racing instead of tuning so money well spent IMO currently. I wasn't the fastest but I now know that it's 100% me that needs to be improved and not the setup. The 3 cars I drove (McLaren 720, Ferrari 488 EVO, Porsche 991 II GT3 R) all drove very similar to the default aggressive setups with no extreme bias towards under or oversteer which suited me fine. Taking Au Rouge flat in the Mclaren and Ferrari, the Porsche is a right handfull at Spa so I've yet to tame that one), I missed Qualifying on one race so started almost last (P15) and finished P5 in the McLaren.
For reference I was doing 02:23.xx at Spa with my own McLaren setup (I'm no tuning expert, or even that good at Spa) and I was doing low 02:21.xx with the CDA setup, delta's were sometimes showing I could do 02:20.xx but I couldn't put it together yesterday (that particular setup is capable of 02:16.700 as seen on the CDA YouTube channel which is pretty damn fast). Yes it's impossible to know if the difference was all in the setup and yes many people are faster than me with the default setups but for me personally, having the CDA setup cleared my head of all things setup related and allowed me to just race, each setup comes with a Motec file as well so you can see the data from their fastest lap with that setup so you can see the work thats gone into it (dialling out negative rake on the whoel circuit and dampers and all that. Before if I raced online and got absolutely smoked I'd always wonder what percentage of that was down to the setup so I'd usually end up back in Practice mode tweaking and testing and usually not end up really getting anywhere after wasting hours and hours and then not be in the mood to race online. With the CDA setups you are still tuning your own tyre pressures, TC, ABS and possibly BB and of course you can tweak anything else on top if you so wish so I can still tinker if I feel like it.
Currently I'm happy paying the £9 something per month if it means my spare time is more enjoyable. Anyone who really enjoys the testing and tuning aspect of the game probably won't feel the benefit but right now, I do. All down to personaly preference obviously and what fits your current circumstances. I'm happy I tried them and happy they feel very neutrally balanced.