I bought the Sheath originally over the Synthesis as it was available in grey. The Sheath is an excellent case but then the Synthesis appeared in grey so I thought I would pick one up, not least to have a backup case as S24 Ultra cases will, I'm sure, start to be less available.
The Synthesis is simply superb and IMO superior to the Sheath. It is far more rigid, including on the lower lip by the charging port, which did start to sag a little bit on the Sheath. The edges actually work better on the Synthesis as they are ever so slightly horizontal as they meet the edge of the screen which makes side gestures easier than they were with the Sheath.
The case feels no larger than the Sheath, something I was concerned about. The Rigid back blends seamlessly with the sides and provides that much greater rigidity overall, again I wasn't sure I would prefer this but I do.
The Sheath is fantastic and is my back up case but the Synthesis is on another level and I can't think of how it could be improved.
Ordering and shipping to UK has been fine on both occasions. Caudabe will be my case of choice for all future phones.