Rather than just upgrade to Snowy, deniro wants to install it and run it and Tiger parallel to each other to decide on a final yes or no.
An additional external drive would make that a bit easier, but deniro's existing setup will make it difficult, because it will necessitate several erasure/clone/installation steps.
By "not inconsiderable" I didn't mean difficult; I meant time-consuming (although there's always a degree of difficulty/hair-tearing/anxiety involved in such a project).
