I've just spent a couple of days testing Connections out and it does everything I want it to do. I'm using WordPress Multisite with a single site installation and with a few tweaks, using documentation and support from Steven, this plugin will allow me to use a single global directory across all my websites. This implementation will save me a huge amount of time, eliminate a lot of duplication and create powerful content. The more time I spend looking through the shortcodes and filters the more I'm realising that with a bit of creative thinking on the setup and the use of templates, categories, families, shortcodes and filters from a directory perspective you can do exactly what you want to. I'm going to purchase all the templates and extensions because I'm sure at some point I'll find a use for them. I hope this helps.
UPDATE: Nine months on - Quick to implement out of the box. However, the more you learn about this plugin the more you'll realise you can tweak it in any way you want...AND...if you don't know the support is excellent. In summary, value for money with fantastic customer support.