I played Billy for almost a year, and every single day since the update. Here are my thoughts.
Just a disclaimer: I don't consider myself a Hillbilly main (yet) because I know most of the Billy mains have been dedicating their time to Billy and only Billy for a long time before the buff was even announced, and although for over a year Billy was the second killer that I played the most, I didn't start playing him and only him until he was buffed.
Adapting to the new Billy as someone who already practiced a lot with him before the buff took a little bit of time but it was nothing like learning the killer from scratch. After a few weeks, I was already feeling like I could differentiate what I could and couldn't do both with and without Overdrive and started getting used to the new changes. Of course, at the start I felt like the cooldown was a little bit too forgiving but thanks to the devs that has already been fixed.
Overall, I feel like Billy is a strong killer, could maybe even be considered the 3rd best killer in the game, and still somehow close to being balanced. However, he might be a little tiny bit overturned and I wanted to discuss the one thing I feel is the real problem.
Lo Pro Chains
Ok for real, this shouldn't be in the game anymore. This add-on was strong even with old Billy but wasn't a problem since he used to lack speed and had Overheat as a mechanic preventing him from using his chainsaw effectively. Now that those problems have been fixed, Lo Pro is the symbol of pure evil. There are so many countless situations where the survivor has absolutely no option to avoid getting hit I can't even feel joy from landing a hit in those situations. If you drop the pallet, you are dead, but if you don't, guess what? You are dead as well. On top of that, Lo Pro removes the basic counterplay to Billy (or better said, a good Billy, since the bad ones prefer M1 to the super-fast anti-loop chainsaw) which is to not waste time healing and instead just doing gens. This add-on should be reworked to do something, hopefully, something that is still fun. And before someone has the bad idea: No, don't make it so Lo Pro makes your chainsaw not insta-down for the entire game. This will not solve the unfun situations of the add-on.
I know a lot of players say that Overdrive is dumb and everything, but honestly, people still need time to get used to it. This is not old Billy anymore and players need to learn that you play differently when Billy is in Overdrive. Also, I see a lot of players refusing to drop pallets against Billy like he is some sort of M1 killer with no antiloop, like yeah maybe with old Billy that would be fine but not anymore. You wouldn't greed pallets against a good Blight, would you?