I had the 6s plus for 2 years and a half. Performance wise, it was one of the best phone I had. In fact, for everyday task, its not that slower than my XS max. The only downside, and its a big one, is the battery life. Its one of the worst I had. The phone become hot easily and battery drain the minute you do something more than just texting of talk to the phone. (watching streaming videos, especially Youtube, was a battery drain fest)
So yeah, great phone, but don't expect a good battery life. The regular 6 had better battery for my experience.