Although both configurations had terrific sound, tweeters on the outside won out. The soundstage is much wider and the imaging is still precise.
I've had the SapphireXLs for a few months now and a pair of Sound Anchor stands were added a few weeks back. I swear the sound continues to improve - the stands made a huge difference but the speakers are still breaking in. I live in a condo so haven't been able to leave them playing for long stretches of time, plus I was away for a week with the entire system unplugged. This past week the system has sounded glorious. And addicting.
Thanks for your advice, Bryan - you were exactly right. Today I'll be adhering the speakers to the stands and dialing them in a bit more. Can't wait!