I know for a long time the Roku 3 and Roku Streaming Stick both had major issues with their WiFi direct remotes causing a huge amount of interference with the WiFi connection they were on due to their single radio design. I'm looking at buying a Streaming Stick as a holiday gift for a family member and I'm wondering if the 2017 refresh fixed these issues or not. I'm not finding much on it that doesn't date back to early 2017 so I'm hoping it's a resolved issue. I witnessed first had what it could do with a couple other relatives of mine. It made WiFi completely unusable for them. I don't need a gift creating problems I have to go fix.
I would suspect that there's no difference. I've not had any issues as you describe with the Stick models 3500 and 3600, or Roku 3 model 4200. Or Roku 2 model 4210 (which is the same device as the 4200). So, since most people had none of the issues to which you referred, it would be difficult to say there's a difference.