Quote - I thought that the main problem with runtimes is that if they reside within the Poser application folder itself it will slow Poser significantly, at least in the preceding versions it did.

Poser always (I wish that could just be disabled...) builds that right click dropdown for the library interface for the active runtime when it starts up or you switch to another runtime. Poser 7 also always builds the one for the Content Collections at startup. So the size of the runtime (and content collection) determins how long Poser will need to switch runtimes or to start up. If you switch or start up with an empty runtime it'll be fast, whereas it will be slow with a big one. (That's why using Poser with an empty runtime and loading content with PRPC and an external browser is my preferec method of accessing Poser content - fast startup times, no time wasted switching runtimes, ...). Poser 7 now seems to work worse with big runtimes, at least it's unable to build the righ click menu for my runtime - but wastes minutes on each startup to try it - same with the content collection I gave it for a try ;-)