just to expand on my rather terse comment earlier I've had a look in the journey planner
Using the HEX
Hex to Paddington
Bakerloo to Baker Street
Jubilee to Canning Town
DLR to Custom House
Journey time = ~ 1 hour
Using the connect service would add ~ 15 minutes
But the HEX only runs every 15 minutes
Using just the tube
Piccadilly line to Green Park
Jubilee to Canning Town
DLR to Custom House
Journey time = ~ 1hr 15 minutes