Why not go for broke and do both?
It seems harder to be inconspicuous with 40 lbs of explosives taped to your body than to wheel it around in a carry-on bag.
Have you seen the size of the average American? Throw on a staypuff marshmallow parka and you'd look like 40% of travelers this past week
Sure, you won't look larger than the average American, but they grew that size over months or years and move naturally with the extra weight.
Strap on 20 - 40 lbs of extra weight and you won't move naturally anymore, at least without lots of training.
No need to carry around all of that extra bulk and weight on your body when when you can pack it into a wheeled carryon bag. You don't even need to keep it under carryon size since the airlines don't (usually) screen for size until you get to the gate.