Location: Noosaville, Sunshine Coast, Australia
I ride in a group and we have different thoughts on droppers. I don't think this is a personal preference category.
To me it makes more sense to have it up when going up hill, support
and down downhill so you can move your butt back for better balance
This will definitely be a riding style preference, and namely, if you prefer to lock-in on your downhill descents and glide or not.
Location: Northern Florida, USA
Not having that kind of equipment this pure opinion, but I thought the intent of having a dropper post was to effectively move the saddle out of the way for climbing (out of the saddle) since the bike tends to be swinging side to side; especially for steep angle seat tube geometry. That being said it does make sense to have lower saddle lower for descending when pedalling is not in play. If pedalling while in the saddle regardless of climbing or flat terrain I would still want my saddle to be at the optimal height (not any higher) for pedalling efficiency (road bike or mtb).
Please educate me!