Had a joplin and a GD - still got the later
Joplin nice but needed servicing and attention
GD Fugly but maintenance free* in the main - Its a spring with some holes in a post WTF are people having to service- ther eis almost nothing there? Had a cable interface issue once on a ride but that is all in 3 ish years of ownership though I do need some ne guides as it has a touch of play these days.
I did once take it apart and grease the spring but it was not really needed but i thought I would
not the prettiest but still AFAIK the only 27.2 one so it wins for adaptability.
Multiple positions is nice on the hydraulic type but you dont use it that often but I would have it if GD offered it but I can live without it.
* TBH neither is that much hassle but think shimano cup and cone for the Joplin and hope sealed for the GD in maintenance terms if not looks .
I can lend you a GD if you want to try one - its not for sale but if you want to know what they are like.