Turnstyle board? Balance board?

So I decided to buy a balance board. Kinda pricy, so I was just
looking at Ebay & Craigslist.

I wasn't sure if I wanted the kind with the hemisphere or the roller.
I use the former at the gym once or twice a week. Might like to learn
to jump, etc. on the roller kind.

I see both those kinds have been discussed here in the past. But I saw
a new type on Ebay, the Turnstyle board. Looks like it may directly
apply to board sports. Has a hemisphere and a small roller and I
think you turn by pivoting on the hemisphere.

I've read some of the old discussions about balance boards. Some like
'em, some say "ride a skateboard". I don't see a skateboard in my
future.

I'm curious if any of ya'll have tried this board?

Also if any of you have preference between hemisphere type board and
roller-type board. Both of those are inexpensive on Ebay.

Thanks,
David