No comparison in my opinion - Erika's straps are extremely comfortable and high quality, while I've always found natos to look good when new, but quickly deteriorate.
I've got 3 Erika's straps, and find they suit pretty much any watch i put em on (all my watches are tool/divers)
The buckles take a bit of getting used to , but once on they stay on. Rather than being a canvas strap, they are made of stretchy parachute elastic.
The old saying goes - you get what you pay for.