I know you are well familiar with them!
Mine is the smallest (12L/3.2gal) Speidel. I love everything about it *except* the height of the bottom outlet. It is just a bit too low for my typical fermenter sludge (about .5 gal) so I can't really use the spigot to transfer. I mean technically I could, but I think it would be more a PITA than just siphoning. I would love to gravity transfer, but I don't see a way around the trub unless I drain some off and hope it doesn't disturb what's left under the outlet. Not sure that would work.
Questions for you:
What size do you use? (30L, if I remember??)
How much trub volume fits under your bottom outlet?