Generally Jet is OK. Most Asian imports do not have hardened spindles. So be careful to clean chucks well before mounting. Bearings range from "Whoflungdung" to top quality Japanese. See other postings for general new import guidelines. Clean off Cosmoline/ protective grease,and fit them well before using when new, drain and fill the reservoires, lube often,Treat them well and they are worth the price paid.
To know by reading is different than knowing by doing. OR:
What you have going into a situation is knowlege..What you have coming out of that situation (providing you survive!) is wisdom.