If you are parking a $2,000 bike and leaving it alone in New York City for hours, two "New York" locks might not be enough.
But, if you are locking a $300 bike for thirty minutes or so, a lower level of security might be enough.
My "low level" security system is to replace quick releases with bolts. I lock the rear wheel with a "mini-lock" directly to a steel pole, with the lock positioned next to the seat tube. That protects the rear wheel and frame. The front wheel and frame are attached to the pole with a medium weight cable with built-in combination lock.
The easiest way to carry heavy locks is strapped to a rear rack. You don't even notice the extra weight.
That set-up works fine in Houston in daytime, on a $300 bike. At night, with a better bike, I would want a couple of my New York locks.