you take care your own. for tight arse like us hobbiest who doesnt want to spend much but expect acceptable performance for a particular project, make your own opamp performance test rig and specify and document your own stock, attach is example from my test pcb for 2 opamp ic. as dave said, its a lot of work, even on a particular opamp type has different clones and performance. attached later is my 3 different 5532 clones performance capture bought from different sellers, i also have rail to rail clone opamps specified, so i know their limitation and know if they are suitable for a project or not. the good thing is all clones that i bough advertised as rail to rail are indeed rail to rail, unlike the non rail to rail clone jellybean version, thats all i care. for pro, dont buy clone, you chap dont care about money so you can order from digikey, ymmv.