I am trading both BitMEX and BitSeven. And as a seasoned FX trader (although my rank here in bitcointalk is still a Newbie due to not posting and interacting since I registered way back 2013) I can tell that BitSeven is a bit of a user friendly and less intimidating than BitMEX.
Leverage is controlled by you the trader and if you don't know what you're doing, you could end up losing your money fast because the higher the Leverage you use (100x), the Cut Loss price is very close to the market price so a quick swing in a highly volatile period could get you liquidated (in BitMEX terms) quickly.
So the idea if you're a newbie in Leverage trading is to start trading with small amount. Ideally, use the bare minimum (0.001 BTC is the minimum amount) and use a small leverage say 2x or maybe up until 5x until you get used to it so that your Cutloss price is way farther than the market price. And if you're analysis is correct, you will have a much better chance of making a profit or getting positive Settlement Amount (in BitSeven terminology)