A few things to add to keep us off topic! I note your bars are traditional round ones. If you look at the Tour article I posted before on handlebar width, drag decreases for each reduction in width, but the last 2 items listed are 42cm bars and 42 cm aero-profile bars, and the reduction in wattage needed to hold 45 kmh is about 15W with aero-profile bars. Obviously, there is a downside to aero bars - attaching lights isn't so straightforward - but it is worth considering. (Obviously, it is easier for pros, as they can have a bike set-up for training and then their race bike, but unless you are rich, it isn't practical for us amateurs!)
And, if you really want to go aeroweenie, no bar tape is quicker as well. On my bike, I just have electrical tape as I got fed up of handlebar tape getting dirty in next to no time and then the thought of the microbiome it might contain started to get offputting... And cutting down the fork steerer tube as well will reduce drag (just the part that stands above the garmin is fine).
In general, going lower should be faster, but it is all about frontal area and power production. So if the new position reduces frontal area, then that is good. You could do a rough estimate by taking a front-on photo and comparing the outline for the two positions. As to whether power production is compromised, then you are into tricky calculations about how much power is lost vs how much CdA is reduced, and which works out better overall. Here for instance, going with shorter cranks can be helpful, as it will allow you to get lower - your knees won't come up so high interfering with your breathing.
The other thing to consider, is is it comfortable? If you aren't comfortable, then that will more than offset any gains you might make aero wise.