Personally, I have been using the alpine butterfly butting up against the "small ring" of a friction saver (though I use an oval quick link for midline attachment). I think the retrieval is easier with redirects and the set up is easier.... for me anyways.
But Steve is correct, even if you just ascend the tree SRT on a base tie....no more isolating throw lines, and you save a lot of energy. Switching to ddrt after ascending on a Srt base tie is very simple and efficient. That's how I started anyway. Ascending on only my hitch on a stationary line.