I’m thinking about whether to buy the A314 spray or the oil. I read that the spray “works fasters”.
Does that mean that the same dose of spray has a faster effect, then the same dose of the oil and if I use multiple doses of the oil I get the same effect?
How long to each of those last?
The environment is an important factor - Sprays are more immediate and less subtle compared to oils, so I mainly use them when I want to make the maximum impact in minimum time. One-off events, mature/high-impact sexual mixes in clubs and the like.
For daily/work use, the slower more subtle/wide-ranging effects of oil is by far the better IMO.
An increased dose of oil can still be very effective, so don’t feel you just have to have both. You just need to do the work to get your dose range and learn the times that are best to go outside it.
Duration - sprays are around six hours per application and you can’t do a lot to prolong it significantly, whilst oils last around eight hours and will run from ten to a full twelve hours if you apply over a a light application of good quality hand lotion. The penalty for this is a slight reduction on overall diffusion range but working up-close and engaging people is where its at, not trying to get hits across the other side of the room! 
To start with and for immediate effects I am in favor of the sprays myself and Mobocaster described everything pretty well. To start I would go with the spray version.
I actually did a write up in my journal if you are interested on A oil in Nude which is for women yes, but I believe the stealth to be the same technology. I compare the A oil to the spray version.
Pretty much the alcohol spray is like a nitrous car where its power is right up front at the expense or lasting power and the oil is like a turbo car where sometimes it takes a little time to set in and work, but once it works it hits hard.
I hope this makes sense.
Now I do not know anything about the stealth A314 as far as the no scent thing, I have the regular A314 oil with the Essential oils they use in it for the scent and it is truly a perfect balance for me as far as scent and how effective it is.
Now with my test with the A oil what I have done with that one to balance things out between the 2 is use 1/2 spray of the molecule A to 1 drop of the A oil and this seemed to balance the 2 out.
To start and test I would probably go with the A314 spray to see what you think if you are just starting out with A314 and then switch over to the oil. This way you can see what A314 does before you jump right in and spend the money on the oil. I think this would be your best bet.
Nice complete answers you’ve got there!
Maybe you should try both and compare? There are two versions of the spray too: A and B. For the whole experience, you can try both spray versions and the oil (separately, of course) in different contexts and see what results, duration and intensity you get 
.