And before that CS. Since the bottom was peeled before I owned the boat, Ablative has been the only type used. It should all be peeled again but I've been scraping and sanding the last few seasons and it's getting smoother. Still covered but I'm removing loose paint and feathering it out. That's a brutal task with an orbital and dust extractor, so I only do it for a few hours. I can't prove it, but I think the boat is sailing better(lighter air) these last few seasons because of this work. That's been the incentive as I improve the surface each year.
The Aquaguard goes on smoother than Hydrocoat and I think the coating is thinner too(I used more Hydrocoat to cover the same area). CS was thicker still as I recall. I think you're right, don't overcoat the bottom no matter what you use. Even thin it to flow out thinner will save you build up over many seasons.