The service from Omori-NA is outstanding. I have had numerous issues with my gauge installs (all little problems, mostly with parts). Greg has been more than helpful with me to get more parts I needed.
The boost gauge I received from Malaysia was a little flawed. The number plate under the glass was screwed a little to far into the gauge. So I have a thin white line around the gauge with it's lit. I don't think I want to bother with another 2 way international shipment... (the other 2 gauges were delivered perfectly)
So for stuff like that, Omori-NA would obviously be the better choice when something goes wrong. But IMO, I think Omori's quality control is pretty good (I haven't heard of a problem posted in i-club).
Lastly, I received my gauges from Malaysia (more like Japan) in 5 weeks.
Take a chance and save money? Pay for quality of service and ease of mind? It'll be a choice you'll have to make yourself.