I totally prefer the Twiggy. I had a Day but sold it because it was just too darn big and deep for me. Finding stuff inside there was like diving into a black hole! Plus, it looked droopy and big on me (I'm small-framed, 5'2").
I used to LOATHE the Twiggy because I was paranoid that it resembled a duffle bag. But...it only looks duffle-ish if it's stuffed to the hilt! If you put a normal amount of stuff inside, it looks like classic Balenciaga slouch. VERY cool and hip! So now I'm on a Twiggy kick! I'm on the waitlist for a yellow twiggy this fall, yay!