"Study level" is an overused cliche, no one really knows what it means. Having said that, I'd call it study level.

I typically fly another company/FSL/Leonardo/Majestic, which everyone (probably) agrees are study level. Having just flown the 757 for the first time tonight (3 flights, 1 autoland), I found that everything that I tried worked well. I didn't note any missing FMC functions, MCP worked well for me and where things didn't work initially, it turned out to be my errors (I'm "sim type-rated" in 737/747/777, but haven't flown a 757/767 in quite a few years).

That's not to say that there aren't some missing pages on the CDU, or that the VNAV necessarily works perfectly (based on others reports). But I didn't find any major issues with the aircraft systems in 3 hours of flight time, so it's good enough IMHO to cover the needs of a typical advanced user.