While transfering btc to other wallet needs payment and in gambling site is so slow.
I wouldn't recommend online wallets at all because right now there is simply no reason to use them - every single online wallet is now charging you the transaction fee and that was the reason why most people used onine wallets - to avoid that costly transaction fee. Coinbsae has added new transaction fees, so has Xapo. Just use a desktop client.
I suggest using exodus, you can store multiple cryptos in there and track their performance. In a sense it is also a web wallet as you can shift your coins from one to another by using the integrated shapeshift function. You'll be ery surprised at how clean and slick the interface is.