I suppose it's time to add in some summarising thoughts (apologies for the long delay - I've been working in Ireland for the last two weeks, and now sat in the airport on my way back
).
My own experiences of the racing has been mixed. I've driven the RB4 and the FXO, and not driven the XRT at all. I fully admit to being a good 2-3 seconds off the best times of the fastest drivers, having little experience of the XRT, but having similar amounts of time in the RB4 and the FXO. I've been using setups from a couple of the old STCC drivers (and to those who asked, this is why I haven't shared them - I don't feel they're mine to share, and I haven't remembered to ask them about it yet).
I've found that driving the RB4 on the stock setup is pointless. Similarly, driving the FXO on stock setup doesn't work anywhere near as well as a good set does. As you'd expect really.
Driving the RB4:
In the sprint races, I've been able to jump past some FXOs at the start and then fend off a few and keep them behind me. I've
found that I can brake later and carry a little more speed to the apex than FXOs can, and perhaps get on the throttle a tiny, tiny bit sooner. However, as soon as we get straightend out the FXO will pull away.
In an endurance race on one of the very short Aston configs I was able to put in a consistent performance, while all but one or two FXOs were dropping pace as the race went on.
Driving the FXO:
In sprint races I did come across one particular RB4 driver who could keep me at bay. One race I didn't get past him at all, the next it took me until the last lap to get by. In that second race my heart sank as he came past off the line. I didn't get a chance to do and endurance race in the FXO, but judging by the state of my tyres after a sprint race I don't think I'd fare very well.
The above is my gut feelings - I've not checked the laps using any analyser. Perhaps I should.
Doing any balancing is going to be very difficult to call. I tried a 1% intake restriction on the FXO for one evening and actually found it helped my tyres last longer and I was able to be more consistent. My club-foot aside, if the idea of this is to make the average FXO driver more level with the average RB4 then will this work?
That brings us on to the wider point. What is this to achieve? If we slow down the average driver, will that have the same, or any, impact on a faster driver? A 2% power restriction may slow down the average driver by 3-4 seconds a lap, but a good driver only 1-2. This could still leave races dominated by a few FXOs, but now those that enjoyed driving it don't anymore. A 3% restriction could make it pointless to race the FXO, in which case we've achieved nothing. Even if we get the RB4/FXO balance right, we've then got to make sure the XRT is also right. :/
I can see some testing needs to be done, ideally with a range of skill in the pack, and a range of restrictions. However, unless we can get something that works we may have to just wait for the next patch. I don't like passing the buck, but I don't think we should change things for the sake of it. We want CTRA to be easy to use, and making people add restrictions that don't work won't achieve that.
On a final note, I'd like to thank those that answered and included their regular preference of car in their post as I asked. Knowing where your viewing the issue from helps a lot. Thanks