I used to do HB somewhat frequently(still mostly did arcade though, as HB really didn't give much reward compared to the time input). I did it for the slower pace, The better chance to get setup and the fact that you had more room to work with. The pace of it was less like a fist fight and more like chess. I could see my defeat coming for me and often because of a mistake I'd made before that I only recognized now. On rarer occasions I could smile as I watched someone witlessly fly into my trap. Even flying biplanes in HB was an incredibly interesting experience. Those same biplanes which were almost inevitably overpowered by the russian reserve aircraft and chaikas in arcade actually stood a chance if you knew how to use them right. You maneuvered in order to put the battle at your advantage. Fight in the terrain you wanted, at the altitude you wanted, at the speed you wanted. You used the clouds to your advantage, because there was enough room to actually hide in them.
Even the lack of ammo could make it interesting. I rarely flew as part of an organized team, but I'd had some success, even after ammo depletion, acting as bait, or trying to herd enemies into areas where friendlies were. You get on someone's tail, and they know you're there, they're going to try to get you off, even if you spend 5 minutes there without firing a shot. Either they want to kill you themselves, that bad that they'll waste all their advantage going after you, a harmless toothless plane, or they'll not realize there's no danger and waste their energy trying to dodge.
HBs were also the only time I EVER got to land on a carrier. Surviving to the point where I needed to was rare, but it's something I love to do to the point where I"ll even load up a test flight with a navy plane and just practice half a dozen, or a dozen takeoffs and landings.
It was just a different experience, and while I won't say arcade wasn't fun, I had my enjoyment there too, that really never felt like combat so much as some strange 3 dimensional sport in the sky where you weren't supposed to tackle, but it happened often nonetheless. HB was... well, I know people will argue about the realism, but it felt more real and I doubt anyone will say that it is more realistic than arcade. It actually felt like there was more at stake, you were part of a team and the team, even a random assortment thrown together and half of them maybe not even understanding your language, were still a team and needed each other to win. There were people who could do well, but the person who could carry a game in HB on their own was exceedingly rare. There were consequences to losing your plane. Everyone has one shot to help out, and if they lost that one shot without contributing, it made it harder for everyone else. And even without counting team consequences, when you spend 5 or 10 minutes just preparing to fight and you're just a stray bullet away from being out of it, that at least is some investment in the battle and some risk attached to it. It promotes more cautious play. It seriously discourages reckless tactics such as head on passes and ramming. It changed the effectiveness of planes when you weren't willing to depend on the stalinwood or the brokenfighter anymore to protect you and those same planes which might be overpowered in arcade turned into still potentially powerful but much more limited in their effectiveness.
So yeah, with that someone incomprehensible rant, I'll just say that HB/RB just as with arcade and the rest of the game has been made significantly less fun now.