It's complicated. The gel tests of 9x17 and 9x19 cause endless rancor and fractious debate--and that among those largely in agreement over all.
The sizes can be deceptive, too.
So, let us consider the Colt Government 380--which is very similar to the Star D, or the Baby Rock 380
It's a comfortable pistol, a three-finger grip, 7 rounds in the magazine.
For all that, it's nearly the same size as a SIG 365X
As in less than 5mm difference in any of the dimensions.
Other than the SIG is a compact, three-finger, pistol with a 12 round magazine.
Naturally, neither are even close to "full size 'service' pistol:
There's inches of difference, not mere millimeters, and the "hand feel" is going to be correspondingly different, too.
Personally, I find them all similar to shoot. That does have caveats: I have near a 50 year history with 45acp in 1911; easily 30 years with the 380 government; only a few scant years with the SIG (if no where near my 1st 9x19).
So, maybe the "missing" component is the hardest one to get quickly: experience.
A person can get good, real good, with the 9x17. I used mine to score a 98 on the TX LTC Instructors test. So, it's possible.
Would it be my first choice if I heard a bump in the middle of the night at home? No, the M4 gets picked then, and for a ton of reasons (many based in experience). That Government 380 has gone on the road with me a time or twenty.
You have to do you. We, in the "gun community" live in a golden age-we can find exact "goldilocks" solutions that fit each of us to as close to near-perfect as possible. (Ok, so, we are like to wind up with several pistols, holsters, and the like--but just how horrible an outcome is that, actually?
)