@tm1v2 on a scale of 1-10, 10 being as comfortable as factory, where are you?
Honestly, I'm at a 6 with these, and was at 8 with the less-fancy MPP Sports, but an inch too low. The adjustment on the Redwoods (particularly the 11k rears) isn't firm to comfortable, it's firm to bouncy and I can't imagine "extra smooth" being in reach. The extra firmness does improve overall handling vs the MPP's but all from rear-end stiffness.
The one time I had 4 people in the car I was expecting to be giving excuses for my extra-firm ride, but it was better... as though an extra 300 pounds in back provided some needed load for the springs. If they're the same spring rates for a Model Y they might be perfect.
I'm thinking of giving Redwood a call to see if 10k rear springs can work because 8k/10k seems like it may be what I need.
@BSinPDX I think you still need more miles on the new suspension. It really did smooth out for me after a bit. Still firm and sporty of course, as I wanted, but smoother in how it goes about its business. At the very beginning I remember thinking like it was even firmer than I expected or really wanted, but after some miles it really did smooth out in how it took in the smaller bumps and stuff. Now I feel like it's goldilocks perfect firmness for my taste, I wouldn't want any softer, it feels like the best ride vs handling tradeoff of any car I've owned, easily. Skewed towards handling of course
but rides just fine while handling amazing.
[ Side note: I run 245/45R18 tires on 18x8.5" wide wheels. I switched our M3P to that ASAP while still on stock suspension. So I have similar sidewall as a base Model 3, though of course I run firm sporty performance tires (weather permitting). Personally I think that sidewall pairs really well with the sporty suspension. ]
From a pure ride perspective vs stock the Performance Sport is...different. In several ways and situations better, in two specific situations worse, but overall it's at least neutral or even an upgrade for my driving. I upgraded the suspension especially for driving fast over twisty back roads, often with pretty nasty pavement, and for that it rides better, in addition to having worlds better handling. Even my wife who's not into car modding at all called it "smoother" than our air suspension Model S after her first long drive through those roads on the new suspension.
The springs are definitely firmer than stock. Yet the ride is less bouncy and much better controlled when the going gets fast and rough. There was something a little weirdly bouncy and unsettled about the stock ride. Not too bad as long as I didn't drive really fast, the stock ride was
fine to me...but nothing special.
When I ride in stock Model 3's, like Lyft and Uber especially lately, I don't feel the ride is better. It's not identical but overall no big difference. This is compared to 16/16 front/rear (halfway firm setting). For sedate driving like that either stock or this suspension is fine. If you want that kind of driving to feel extra smooth then the GT kit would be the way to go.
The firm springs make themselves known most when driving slowly over rough city roads. Like <= 30mph or thereabouts. But with the dampers at 16/16 it's not harsh, just firm sporty. The harsher the impact the
better it feels vs stock. Minor stuff is not filtered as much when going slow.
The other situation it can ride worse than stock is wavy highway pavement. I don't encounter much of that, but when I do the suspension likes to just follow the waves up and down. It does keep the weight planted and is probably good for handling but doesn't make for a great ride in that situation. Stock suspension was softer sprung and softer dampened and would absorb some (not all) of the waviness, effectively reducing the amplitude.
The odd wavy road aside, the faster I drive the smoother it gets vs stock. That's when the DFV really comes into play I think. And it's also when the stock suspension was at its worst.
Similarly, the rougher the road the better the ride vs stock (except when going very slow where the firmer springs just can't compress as much). The stock suspension would get unsettled and lose control over the rough stuff especially going fast over it. Now the car just takes in the bumps while staying stable. You know the bumps and pavement under you, it is firm and sporty, not soft or floaty, but with any significant speed it's smoother than stock, less crashy and less bouncy and much better controlled.
Hitting the rear bump stops (easy on a Model 3, stock or modded) is a
vastly smoother experience. Night at day. Hitting large dips and bumps at speed was pretty bad stock. I found that out even on our test drive.
Normal highway driving feels tighter. Not harsher, not smoother either, just tighter responses, and no more float or bounce from the bigger dips.
I hope this helps. If there's any more specifics you want my impressions of or for me to test, including specific damper settings, just let me know.