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It can get a little dangerous, but acceleration and cornering are still the twin Kings of the Pitch. That much hasn't changed. Even playing Seeker it was a rare day I got up over 100 unless I was diving on a Snitch.
That's what I meant by referring to you as a fellow enthusiast. I got my first racing broom and started competition in children's class racing when I was 6. Still, over my years of giving flying lessons, I've come across any number of people who were convinced they were pants at flying because they couldn't do anything right on the school brooms. Always regretted the thought that the sport may have lost more than a few who weren't born with our advantages.
Small improvements, evidence of a different way of doing things, of thinking about how the spellwork is assembled. You know as well as I, once a competent broom boffin sees something is possible, they will set to figuring out how to make it work. Just as likely the method they discover will be something never before seen in my time. Or maybe, the improvements that are from my time already have their roots in yours. Above my level of Arithmancy, if you know what I mean.
If you'd like, we can get together some time next week. Give you a check ride, set you up with some rule books from my time. I'm thinking I should also give you an unspelled but otherwise ready to go broom to set up free from any constraints of everyday use, give me an index of where to start any further instructions. No sense wasting your time on something you already know. That sound like something you'd be interested in?