What is copy meaning in this case?
An almost exact, feature-by-feature, replication of the Rigol DS2000A-S (with better specs, it seems - as well as the 4-channel and MSO options) - at almost exactly the same price point. The MSO/SDS2000 also has overlap with the Rigol DS1000Z and MS/DS4000 - but it's closest in price (at least, the 2-channel versions) with the DS2000A series.
But I'm not using 'copy' as a bad word. The copying of successful products (but with improved specs, features, price, etc) drives the marketplace all the time. I only used the word because I think it's important to acknowledge these products will be competing head-on in the same price class - and it's essential to have someone who has used the Rigol for awhile make a comparison.
I don't have a stake in this comparison either way: I like my DS2000 - but it has plenty of faults / missing features. If the Siglent is the better product, it's important for prospective buyers to know about it and give Siglent a big success - because the more Chinese companies producing good quality T&M equipment (and getting rewarded for it), the better it is for all us end-users.