They're pretty much the same as any other Registrar.
The only difference is that you are signing up as a reseller and get your own reseller website, which would be something like GetItNow.myorderbox.com.
Then you sign up as a client on GetItNow.myorderbox.com (so you are your own client).
You get domains at their reseller prices, which depends on how much you've spent with them or deposited in your account. The prices are reasonable.
I think Whiz.in and a lot of other companies are just resellers at Reseller Club.
Also, a lot of people have their domains at a Reseller Club reseller, and you can push your domains across resellers as if they were all just one big registrar.