Overall I've found it to be the cleanest event for past few weeks at least. Similar level to you at 33.3 in the 458 and starting between 3rd and 10th in B/S lobbies. There's the odd race where you're forced to lift off a bit through the esses due to cars in front and person behind you decides to barge through instead of doing same, but find if they're driving that flat out, you can usually get the spot back before too long when they push too hard (assuming they don't spin you out).
Only real drama I had last night was getting put in to a lobby with mainly SR A's and B's. Started 3rd, on pace with top 2, when the peanut behind me decided to use me as his brake at T1 on Lap 2, knocking me back to 5th. Got back to 3rd before back straight, then 2nd place as guy in front had a penalty and I wasn't too far back from 1st. Coming down pit straight, checked mirror to see if the peanut from before was in striking distance and nope, was a mile back. Or at least that is what I thought, before hearing the familiar screech of tyres from my left as I made my way around T1 before getting punted off the track again at T1, by the same guy.
Same guy, same corner, 2 laps in a row
Made my way back to fourth somehow (presumably because these idiots kept taking each other out).
But in general, I've been finding the Race B's really clean this week.