It all depends on our injury. Some guys love highway pegs. i think they put weight on my hips.

 

I keep the highway pegs on my bike so I have a place to put my padlock. I never use them for my feet because they make my back hurt. I'm 6'1" with a 34 inseam if that matters.

 

It's not that the bike is uncomfortable in general, it's that it's not setup for you.
Also it's not harley's issue that you bought a bike that may not be right for you.
I did a ton of research for my height, and expectations. I ended up with a Fat Boy 114 and its EXCELLENT.
It's a comfy bike for me and my gf to do 2 up rides on for hours, and go camping, and its also great for my solo rides tearing up the twisties, and being a menace to society.
Do your research before purchasing a vehicle.

Since you already bought the bike, go to GetLoweredCycles and look for the Saddlemen Explorer series of seats for the M8 Softail Slim FLSL(DO NOT BUY THE TWIN CAM SOFTAIL SLIM SEATS!).
It's a very comfortable seat. OR check out Mustang Seats.
The seat you have on your bike is probably a show bike/dicking around in town seat.

Then go get your bikelift out, put the bike on it, grab your hex bit sockets, and other tools and sit on the bike and adjust the bars and controls angles till it feels right and everything is easy to reach.
Most of comfort is setup, go set your bike up FOR YOU.
It's setup for someone else right now.

 

I wouldn’t say you shouldn’t have bought that bike, a seat change makes a huge difference.
Not counting exhaust it’s probably the component that is changed the most, an old saying I used to hear was Harley make’s Motorcycles, not seats. Meaning they don’t put a lot of effort into it. Most dealers also have Demo seats you can pop on and ride, but again Saddlemen and Mustang, have been my go to and a few others that are good

 

Maybe it's just the seat. Maybe you just need to break that seat in a bit. I remember when I bought my first Soft tail. I changed the seat. Cost me $575. I road around on that for a couple months and wound up putting back on the original, and never took it off! New seat, can be like new shoes sometimes. Give it a while longer. Maybe even try adjusting your handlebars a little bit? Not trying to be a jerk, but you did say it was your first Harley and forward controls...Never know.

 

These will help with the turbulence somewhat, not fully but will eliminate most of the buffeting.

Cooling deflector wings, deflect some of the air down onto the engine instead of coming up over it.

https://www.dkcustomproducts.com/coo...t-softails.htm

 

The uglier the seat, the more comfortable it is. Lower the windshield.
My knee has been screwed up for 10 years. I put extensions on the floorboards, good for 10-hour days.

 

Seats like that are not made for long distance riding, they're made to look good around town. A seat like the Harley Hammock might not look as slick as your current seat, but it'd probably help a lot with comfort. The Harley Hammock also has the option for a removable rider back rest for longer rides that will help a LOT with back pain. These days a back rest is a must for me for anything more than a 20-mile ride.

If the handlebars have you leaning forward, then pullback risers or taller bars, or bars with more pullback might help.

For the buffeting, the only thing I've found that significantly reduces or eliminates buffeting, besides removing the windshield, is fork-mounted wind deflectors like the ones made by JES Customs. As you've already identified, the buffeting is caused by the wind coming under the windshield, up the sides of the tank, and rushing into the low-pressure area created by the windshield. Removing the windshield (or a very short windshield) gets rid of the buffeting because it eliminates the low-pressure area and puts your head in the clean airflow.

It's a good-looking bike, it just needs to be customized a bit to fit you and your riding style.

 

The Softail slim can be plenty comfortable. First off: did you set the appropriate preload for the rear monoshock? Eventually you may consider replacing it.

As others have mentioned, check out Mustang's touring seats or Saddlemens explorer seats. There are other brands, but these are the ones I have the most experience with and those product lines are quite comfortable.

As for the windshield buffeting, I recommend looking into Harley's Wind Splitter. I had the same issue with numerous windshield on my last Softail, but the Wind Splitter solved that issue. If you don't do a lot of long distances or 75mph+, you might forego a windshield altogether.

Best of luck.

 

I have a '23 Heritage myself.

The Sundowner was the seat for me. Almost "cradled in the hands of god" comfortable. Surprisingly cheap new as a 2-up seat. You can go with a solo version, but you'll have to buy used or old stock somewhere to get a solo as Harley no longer offers it. Not 100% certain about fitment on a Slim. Visit a dealership that has the demo seats and see what feels good to you.

The oem windshield joggled the hell out of my head as well. Riding without is much cleaner air. I went with the widest, tallest, Clearview windshield, with a vent. Makes me happy to sit behind that gigantic barn door with my helmets face shield up. I actually didn't need to go quite full height, but so be it. On the plus side, the bugs do indeed go flipping up and over quite high.

I also changed my bars to Helibars, for adjustment. Not 100% perfect, but pretty durn close.

I am satisfied with the suspension in stock form, for the way I ride.

The oem tires, well on the Heritage, they ain't impressive. I'll likely replace them with Cruisetech tires when they wear out.

Rare for me to find a bike that fits me perfectly right out of the box. In fact, can't think of a one that ever did.