Xapo its working great for me so far. The problem you describe is when you have less than 10.000 Bits in your account. They requested this as way to ensure that the miner fees are covered when you transfer to the blockchain.

They are not a scam, actually they are one of the most well funded Bitcoin startups in the Sillicon Valley. Way more secure and more reputable than  Blockchain or the cocky asses of Coinbase.

Larson