I don't see the added benefit of pooling coins in a POS setting above doing it yourself in your wallet. Well, minus the work that it saves you.
The main benefit is the reduced orphan rate. A staking pool allows a bunch of people to cooperate, and effectively agree not to orphan each other's blocks.
Then there's the fact that most people don't keep a server online 24/7, and so a staking pool allows them to be always staking without having to maintain their own server.
There are lots of downsides of course, with the biggest being the counterparty risk and the fees you'll have to pay.
Proceed with extreme caution it appears to be a black box you put money into and a trickle of money comes out of because magic or staking or something. If you wish to withdraw principal you pay an unspecified penalty. Transparency about zero as far as i could find with limited digging.
I've not looked at their site, but there's no excuse for such a site not to offer a proof-of-solvency, so its clients can be sure they're not investing in a Ponzi.