A first impression of a perfume misleads you almost as much as a first date, so I don't compare two versions of a scent at the counter but over two quiet days.
I have fallen in love with a scent at the counter many times, on a paper strip, in the half-minute while the sales assistant talks about bergamot. Almost as often, by evening, I have been disappointed at home, when all that love had left on my wrist was something quiet and unfamiliar. So I no longer compare two versions of a scent on the go. I give each of them a whole day, from my morning coffee to my pillow, and I'd suggest you do the same.
One day, one version
If you put both on at once, one on each wrist, they will start arguing. By lunchtime, you won't know which cloud belongs to whom, or which of them you actually liked. I wear one version in the morning, before work, and the other the next day. I try to make those days alike: the same weather, the same jumper, the same coffee. No new hand cream and no evening in a noisy bar in between.
What I write down
I don't write much. There are three lines on my phone: what I felt after five minutes, what after a couple of hours and what was left on my collar in the evening. I've banned the word "stronger", because it says nothing. In its place, I write what exactly grew louder, the wood, the sweetness or something green, and whether I want to bring my wrist to my face again.
After half an hour, I usually stop smelling my own perfume, although, in the lift, other people can still smell it perfectly well. I don't reach for the bottle to add more. Instead, I ask someone I trust to lean in towards my neck and tell me, honestly, what they smell there. That answer means more to me than anything written on my phone.
What decides it
For me, the winner is not the version with the brighter opening, but the one I came back to, on my own, in the evening. Usually, I realise it with my nose buried in my own sleeve, just before bed. This is my experience, not a law, and your skin may well judge differently. But a first impression has never yet had the last word with me.