Comparing Directstream 1 and 2

I have one more week left in my 30 day trial of the PS Audio Directstream 2. I’ve had some personal (medical) issues which have limited my listening. Also, even though I know better than to rely on reviewers’ opinions, I’m a little put off by the unusually negative review in Stereophile. My wife, who has better ears than me, has offered a couple of hours to compare my current Directstream 1 with the Directstream 2. Here’s my question: What order is most effective for the comparison? is it better to begin listening to my current 1 and then listen to the new 2 or vice versa? Going back and forth takes me a while —there are 5 or 6 cables to move—and my wife will get impatient so I won’t be able to do very many comparisons -maybe 2- with about 10 minutes in between for set up. I also would appreciate any other suggestions for this momentous comparison-what to listen to (we mainly prefer classical and soft vocal options), how long to listen before switching, and anything else that might help. Thanks,