Sora 9 speed are pretty much like the previous generation of Tiagra 9 speed, trickle down.
Just make sure you get the paddle versions, not the old Sora thumb trigger versions that were 8 speed with Sora, but carried over for a year or two when Sora went to 9 speed, but then they changed them to the paddle version.
Sti's are just nice to use, smooth, light shifting, and compared to bar end shifters so easy to shift, so we tend to shift more often -- which has benefits on our legs and overall riding.
I've ridden on all kinds of shifters and love sti's, my 15 year old Tiagra 9 spd are still shifting fine, and really, Shimana sti's are in general very long lasting and reliable.
It's up to you if you like bar ends that much, but its a no brainer that sti's are easier on our hands and less hand moving around.
You mention not being in the drops that much, so consider the varied options of dropbars that have much shallower drop (distance from tops to drops) and shorter distance from tops to the curved part of the drops---without knowing what bars you have on your bike, you might appreciated more "compact" drops, they are really nice and a real change from older style dropbars -- again, we don't know what you have
dropbars with a slight flareout are also really nice, again there are tons of options out there nowadays due to the gravel popularity.
About ten years ago I put Salsa Cowbell dropbars on my tough touring bike, and the 12 degree flare of the shallow drops is great -- not too much, but just nice to make being in the drops more useful
oh, the one thing with triple front derailleur sti's is that there is an audible "clunk" when downshifting to a smaller chainring
Not silent like front friction shifting, so that takes getting used to.
My touring bike has hood friction front shifting and hood indexed (or friction if you want) rear shifting
Friction front shifting is still really nice, but sti front triple shifting is fine too, its just noisier at each shift (we don't shift that often really)
While you cant fine tune front shifting as much as with friction, shimano has a great feature called Trimming, basically "half shifts" with the front shifters, so if you are in the middle ring (I assume you have a triple) and you start to get towards the smaller cogs at the back, the chain can start to rub the fd, but you do a little "half shift" towards going to the big ring, and the fd moves over a smidge so that you don't have any rubbing -- super useful and intuitive to use
this trimming sort of half shift stuff has been on shimano sti's for ages, easily 20 years I reckon, and it just works.
I was recently borrowing a ten speed Tiagra bike with a double crankset, and the left shifter had this.
Tiagra is up to 11 speed I think now.
if you want to stay 9 speed, Sora 9 spd shifters are a great option.
Or you could go to ten speed easily and get 10 spd shifters, but I think with your 9 spd era rd, you might have to look into microshift or something.
Ive installed 9 spd microshift sti's on a bike, and the Sora have a nicer feel in my opinion, both hood feel and shifting, but I'm not up on the latest versions.
cheers, and good luck