Depends on what you've been on in comparison...
I found it awful... I couldn't care less if it spins like crazy, it's not comfortable enough to be anywhere near enjoyable... It's rickety, it's rough, it's absolutely diabolical...
Is it the definite worst? Quite likely, it's definitely down there... There's PLENTY of coasters I'd rather ride for a continuous hour than Whirlwind and that probably would include Sequioa Adventure (although lots of money would have to pass hands for that to happen mind)... I've been on plenty of SLCs and Boomerangs that feel like B&Ms in comparison to it as well, it's literally the definition of awful...
Spinning like crazy does not make a good ride, especially when it feels like said ride is probably going to collapse...