I have played both thoroughly and here's my report:
The Sterling Ball basses are amazing for the price. They sound and feel and look just like the real deal. It's not until you pick them apart that you see the differences.
The wood quality of the neck is my major beef with them. I had one that was good. The grain didn't look bad or anything, didn't look great. It held the neck true and was all good.
I had another which kept back-bowing and it was essentially defective. The fretwork was also not great.
If you look into the used market for the US basses, you can find instruments that aren't much more than a new SBMM, but have:
a) better woods
b) no build issues (because faulty ones were warrantied), and
c) instruments whose value isn't plummeting.
Plus, the older ones are starting to appreciate in value. The days of going to GC and finding a used MM for $500 are over, so that is good news for the future of their used gear.
If you did get a new SBMM Ray 34, let's say, and it wasn't perfect, it does have a warranty, so if you have issues, they'd be responsible to make it right. And I do believe that you could get one and have a good tech make it play perfectly, if you spent the money with the right person...
But why do that if a good used USA model can be had for the same money?