Performance is a consistent issue. Ive had to build a lot of optimization and benchmarking tools in order to keep things functional. Every couple of weeks I have to refactor everything to keep load times good. Both on the database side and on the lisp side. The models, by default, will happily build functions with 26 database calls or millions of recursive steps.
More frustrating, though, was probably the 3-4 weeks when i migrated the storage concept to "one big tree". This was an aesthetic thing that I later found out some of the old lisp machines also did. But - I didn't think about it initially when I built it. And switching things at that low level was difficult. There was a lot of legacy data stores along the way and programs were using the old store constantly. Very irritating. I still wonder if it would have been faster to just completely rebuild at that point.
An ambitious user could probably run it themselves and have it function, or I think I could run it as a managed service for somebody and have it be good, but the UX is still not really ready for primetime