1) Upgrades are easy and speedy, as long as the site is not modified. If it is modified, there's no way to avoid any problems, no matter how system is designed. We are gradually improving separation of components (modules, templates, DB) and that's as much as one can possibly do in web script.
2) What exactly do you mean by API? What kind of functionality?
1) something that makes upgrades easy and speedy... on a production site, dolphin will stopping to work (almost in part) ...
2) a set of API to share with other websites
without these listed above, other platforms may take advantage behind dolphin one.
imho
2) What exactly do you mean by API? What kind of functionality?