They are about the same price but the Passport has a max charge rate of 8amps and has 100watt of output power. The 0606i has a max charge rate od 6amps and output power of 50watts.

The Passport Ultra will let your lipo needs grow - ie will charge higher cell counts, the 0606i will not. As most find out in this hobby, needs tend to grow over time, Passport Ultra provides some 'headroom', the 0606i does not.