I've seen them both. For some reason I didn't review Zara.
I'd see them both again, however Lena would possibly just edge it.
Zara is certainly bigger than the profile pictures would suggest ( at least a size 12 when I saw her) at the time I saw her. Whilst although no major negatives, Lena, at the time I saw her had some stand out positives, primarily her figure at that time.
**Rereading this post before posting, I'd say Lena just cut it for me: exceptional body at the time, beautifully tidy minge, Great tits, that's my vote cast