I have used both Steeda and H&R lowering springs on my 2021 Explorer ST. I am currently on the H&R springs. I also have the Steeda rear sway bar installed and was used with both spring sets.
I put about 8,000 miles on the Steeda combo. I have around 800 miles on the H&Rs now. While the Steeda lowering springs do not lower as much (especially noticeably in the rear) they absolutely 100% handle better than the H&Rs. They are more hardwired to the ground, and lateral handling and steering input is noticeably more crisp. With that said, the Steeda springs are noticeably stiffer, you feel bumps in the road more, but I wouldn't say it makes the ride harsh, unless you are going over pot holes or irregularities in the road, then it is more noticeably rough than the H&Rs.
The H&Rs are noticeably softer, and I noticed in comparison to the Steedas are a bit "floaty boaty" meaning the suspension isn't as responsive, or controlled and tends to float over bumps. It feels more like an SUV. The H&Rs are more comfortable, compliant and ride better especially on the highway. The floatiness I feel could probably be better managed with slightly stiffer shock valving. The Steedas have noticeably better lateral handling, but with less front end "unload" (weight transfer) during launches, which can make launching a bit more of a challenge with tire spin if you are drag racing.
With that said, I think the H&R springs are probably better for drag racing, while the Steedas would be the better choice on a road course. The H&Rs can sometimes "bottom out" (on road humps) in the rear (just have to go slower over speed bumps and road humps), there was no such issue with the Steedas, even with passengers.
Steeda Pros:
Better, more precise steering "feel"
Better turn in response, better steering feedback with road/tires
More hardwired to the ground, but not harsh ride
Better lateral handling
Feels more like a sports car than an SUV
Steeda Cons:
Ride noticeably rougher
Not as comfortable for a daily driver
Don't look as good installed since they don't lower as much as the H&Rs
Lower in the front than in the back
H&R Pros
More comfortable for daily driving, especially on the highway
Better weight transfer during launch (straight line)
Chassis looks less SUV-ish, looks BETTER
Front and rear lowering bias even
H&R Cons
Don't handle as well, more side sway despite having the Steeda sway bar.
Less precise steering input feel, less communication feedback with steering wheel to tires
Tends to feel a bit floaty boaty in comparison to the Steedas when going over bumps or imperfections. I noticed this almost immediately since I drive the same roads every day.
Rear tends to bottom out over road humps/speed bumps
Feels more like an SUV than a sporty vehicle (I'm sure it's better than the stock springs though)
Steeda side:
View attachment 7612
H&R side:
View attachment 7613
