Going by the specs, there are little significant differences between the 863 and the 860 EVO but, as you said it's an older drive. Samsung SSDs tend to get better in quality with each new model. One possible problem is many enterprise SSDs have far shorter data retention times when left powered down for extended times, sometimes as little as two months, compared to the year or more of newer consumer SSDs. Also, if your source isn't a Samsung authorized distributor, you may have problems should you ever need to make a warranty claim.
A new 2TB Samsung 860 EVO 860 costs around $85 more but I would feel safer getting the newer model.
It seems like it should be a super great drive because of that extra endurance. It's using MLC instead of TLC like what's typical today. It also already has 3D-NAND chips from Samsung and not the previous "planar" ones, so it's not using old technology.
Overall I'm thinking it's better than the modern 2TB SATA drives. It should be a lot more expensive. I'm thinking it's comparable to the current "Samsung 860 Pro" which is $500 for a 2TB size.