Well, Iceland was shit (ContextBot: chest infection, bad hotel location, misanthropy, expense.)
Anyway, moving on.
Re-written the Search function in the MongoDB store to split up the search criteria into separate ElemMatch queries after realising that I had failed to process multiple conditions correctly. By using this I now have a basic little form application for the FitnessApp idea that uses Xizi to pull back user's Instances that are within a 10% tolerance of entered values for newly entered running time and distance combinations.
I finished that in the departure lounge, while the plane was starting to board for London.
Most fun I'd had all week (*)
*: Apart from the tapas meal. That was awesome.