The myCharge HubPlus 6700 is slightly larger than a deck of playing cards. It comes with two attached charging cables - one with a lightening connector (e.g., iPhone) and one with a micro-USB (e.g., many devices and phones, but NOT Apple), as well as a USB female slot. So you could, theoretically, charge three devices at the same time - assuming two of them required a different one of the available connectors, and you were carrying a USB cable to use with the third device.
The HubPlus 6700 is a bit heavy, but that's because of it's 6700 mAh charge capacity - you can get lighter portable chargers with less capacity. My other portable charger was smaller and lighter, but required a USB-port power source for recharging, so not always convenient to recharge. What I like about the myCharge HubPlus is it uses a regular wall-outlet charging plug. So if I'm traveling without my computer and need to recharge my HubPlus, I can just flip open the plug and plug it into an available 120VAC outlet. I never leave home without it, and always take it when I travel.
The built-in charging cables are a bit short (~3" to the end of the connector), but that's to make them store snugly into the side of the charger when not in use. Much longer and they would hang out. However, they are a bit awkward to maneuver after attaching a device - for example, I like to sandwich this unit with my iPhone while charging it, and that requires the cable to twist in a direction counter to it's natural orientation. Not a biggy, but if they moved the power switch, which is currently on the same side face as the built-in cables, it might give them an extra 1/2 inch of cable space. Disclaimer - I don't know what the inside looks like, so it may be that moving the power switch would not be practical.