I’ve tried two. One Max 24 core which I returned just because I needed more than 512gb of storage and I didn’t want a machine that was (ever so slightly) slower than my 32 core Max 16”
That was like brand new. Same warranty apple care box inserts etc. The box just doesn’t have a nice photo.
I then got an Ultra 48C. Again like new, you wouldn’t be able to tell this thing was refurbished at all. It’s like brand-new. I will note for the curious though, I added a lot of 4K H-E-V, with effects and so forth. The 48 core ultra is may be at best 30% faster than my max laptop. I would not have purchased this full price if I didn’t get a deal. But for $3500 it’s not bad for an extra 30% jump over the similarly priced laptop.
Another plus is these things especially the ultra a backordered like two months, so definitely worth getting referred from Apple. I bought them before it’s a decent little deal you save a little money and you get things quick