I agree with the "on/off" part but I feel like when he starts to try force physical play he plays worse and wish he would just be physical when the time presents itself.
I feel like it his honestly him being smart with the choice of either physical or not physical and not a negative. Sometimes guys get carried away with playing tough and forget their assignment is to stop the puck from getting to the net.
In my opinion Seider has been quite good this year, and people are like expecting perfection with every single play which isn't true of any defender I have ever seen with the exception of Nick Lidstrom. Lidstrom would rarely make mistakes, but every other D man I have ever seen while some being HOF'ers and great D make the wrong play from time to time. Seider to me is doing exactly what I hoped he would do, and making smart plays in both ends about 95% of the time, with the occasional miss. I do wish he would shoot more as he does defer to others too much, and I think him shooting more would at least make him and our offence less predictable at times as on the PP they know Seider is likely not shooting.
Way too many GDT where people are complaining about Seider, when I don't think he has had any game I would say he was bad. There was one where he wasn't great, but he was still solid.