FWIW, I'd go with whichever one you think shows his strength more.
I sent a portfolio for DS6 in May, as he was missing achievement scores and he was admitted. I debated which reading video to send -- one from his 5th birthday where he was fluently reading a 2nd-3rd grade book or a more recent clip which showed him reading more complex words fluently.
I ended up sending a link to a short video w/clips (~ 2min) of (1) him reading right at 5 and (2)a recent clip of him where I had him read a few paragraphs from a middle school history book he hadn't seen before, asked him 2 or 3 questions about the text and had him do a bit of mental math. Good luck!
