2021 STX (146) vs 2017 STX (137)

[Tc_027]

I currently have a 2017 STX 137 with a SeatJack for our 7 yr old daughter.
I don't love the rear ride of the sled even when I'm alone on it.
I'm wondering if a true 2 up like the 2021 STX (146) would ride any better on rough trails?
I obviously ride a lot slower with my daughter than when I'm alone.
How about higher speeds?
I know I currently have a 1.6" lug and the 146 is a 1.25" so I was wondering if there was a big difference in top speed? I thougth I read somewhere a 10 mph difference?
Any advice would be appreciated

 

[sailor joe]

I have a 146 stx, it moves fast enough ...it probably doesn't handle as good as a 137 but they are 2 different sleds.