So here is my MX350 experience so far. All applications to the side / front of the neck.
First use:
1.5 sprays (the half spray being the first one from the bottle) - nothing noticed from me, my partner or anyone else.
Second use:
2 sprays. My partner was quite relaxed about things which was good, given she has been quite stressed about work lately. Self-effects were the same - almost a feeling of being too tired to care about things but without any lethargy. I just felt like nothing was worth getting bothered about.
It didn’t effect focus or energy though - I went to the gym and still put in a good 60 minute bout of self-destruction! This is where it got interesting.
Girl 1: coming through door to gym as I went into changing rooms. We passed, I held open door and she made eye contact but no smile or “thanks” or anything.
I got changed and went to the cardio room and she was on a stepper, I went on the bike next to another girl. Zero response from the girl next to me. The girl on the running machine 6 foot away glanced over occasionally though. MX350 or not I don’t know 
After 10 minutes I got off the bike and went on the running machine. A few available so didn’t go next to the girl who was glancing but a couple down from her. She didn’t look again, though, that I noticed. By this time Girl 1 had got off the stepper and onto the rower and I had to walk past her.
5 minutes into my time on the running machine Girl 1 got up off the rower and onto the running machine next to me. Of 8 or so available and with no obvious reason that’s the one she chose. Her finishing on it coincided with mine too - as I slowed down to a 2 minute walk finish she did the same, just 30 seconds behind, so I’m taking that as a hit.
It’s worth saying that this isn’t a gym where I’ve ever noticed a great deal of flirting or IOI’s between anyone - it’s quite “serious” and not that social. All girls were mid-20’s age.
Third Use:
Three sprays, mid to late 20’s girl sat near me waiting for a train although other spaces were available. Not necessarily a hit, but on the train I thought I’d try it out and walked past empty seats entirely unnecessarily before sitting down a whole carriage length away from where I got on, and by another set of doors (so not a convenient way to board a train if that’s where I wanted to sit). As I sat down she walked past me having followed, and sat behind me. Hit I think!
In a shop I got a full refund without asking for it due to shoddy service - this was from a man so I don’t know if 350 has some respect or status vibe too. They did a bad job, and not only did it again for free but refunded me and like I say, it was without me even complaining or asking. Very unusual.
I need to use MX350 more, but I’m starting to draw conclusions about what it does at 2 to 3 sprays. I’ve seen hair colour mentioned in respect of MX203 / MX350 and all were brunettes.