I kept track of all the cars I got from spins, here is my top 10 best rewards of both types of spins.
That is after 10 hours of playing and being level 124 (with VIP). I did buy all houses except the 2 castles so a lot of extra super wheelspins came from there. Still, I feel like I do normal spins a lot more than super spins
NORMAL wheelspins:
1) Alfa Romeo 8C (Forza Edition)
2) VW GRC Beetle (not in autoshow, 500.000 value) (I even got word from Kira after the spin this car is really special)
3) 1979 Chevy Camaro (not in autoshow, low value)
4) Mercedes W154 (10.000.000 value)
5) Ferrari 365 GTB/4 (600.000 value)
6) Lambo Aventador (310.000 value)
7) Aston V12 Vantage S (240.000 value)
8) Lambo Diablo SV (174.000 value)
9) 1973 Nissan Skyline H/T 2000 GT-R (170.000 value)
10) Holden Torana A9X (130.000 value)
SUPER wheelspins:
1) Lambo Aventador (Forza Edition) (maxed out on skills, this is an ABSOLUTE skill farming BEAST in the area south of the windmills)
2) Alumi Craft Class 10 buggy (Forza Edition)
3) Ford Falcon GT-HO (Forza Edition)
4) VW Type 2 (Forza Edition)
5) Bentley Continental (Forza Edition) (saved me 300 FP which I used to buy 2 extra super wheelspins)
6) 2004 Subaru WRX STI (not in autoshow, low value)
7) 2010 Golf R (not in autoshow, low value)
8) LaFerrari (1.500.000 value)
9) Charger Daytona (900.000 value)
10) Tamo Racemo (600.000 value)
(only listing the top 10 here but there are 6 more cars after the Racemo that have a value of over 200.000 credits)
I know this is just me being 1 person but to me it seems the statistics show that super spins indeed give better rewards. But having that said, super spins can be absolute crap as well, like 2 pairs of shoes and 40.000 credits or so...