I'm in a similar position. Routinely give up massive amounts of weight (and 20 years haha) and usually struggle for it.
On the rare occasions I can find a match closer to my category I find people feel really light and I actually get to feel like the strong one for a change.
I'm between 72kg and 75kg normally (sorry, I don't know that in freedom units), and I stopped competing at open weight about 5 years ago and also try to avoid heavier guys, even in training. I'll normally go about max 90kg with training partners. We've got a few guys we'll over 120 KG, and anytime I roll with them, which I normally avoid, I'm just avoiding getting injured.
Being the heavier guy is DEFINITELY an advantage. I always find it funny when I hear people say "size and strength don't matter", when it's also normally coming from heavyweights on steroids. Yeah, when there's a huge skill discrepancy, then things can balance out, but if two people have a similar level of skill, then the bigger and stronger guy is going to win.
Never, but I'm in the big boy class anyway at 275 lbs. And I guess the minor technicality that I don't compete. My wife competed a lot for a few years and the only time she ever competed in the correct class (~150 lbs) was at master worlds. Every other tournament she entered she was giving up 20-30 lbs, but she still did really well. She regularly trains with me, so those ladies probably felt light.
back in the days in early 2000's, i was 56-57kg and there was literally nobody at this weight.... if i wanted to compete, i had to take on people heavier, no choice
For example, I won the european shooto runner-up tournament in the -65kg category weighing 56.5kg because there was nobody under 60kg so they can't do the category.
same about the training.... for a long time i had no sparring partner under 70kg ...
i would say that it push you to get your technique almost perfect to be effective, but your body don't like it on the long term.
now 47yo (herniated cervicals, torn ligaments etc), i only roll with light guys or long-time advanced partner who can roll smooth