When using a changing bag, I use to use a cardboard box that would fit inside so I could keep the bag from laying on top of my hands and film.
Started with plastic, loading was mostly difficult although sometimes it worked ok. Then switched to stainless steel after finding that the quality brands like Nikor or Kindermann loaded easily every time. Now a days, if buying new, Hewes is the brand to get.
Returned to plastic only because that is what Jobo uses, however, their plastic reels are pretty good. Now they have stainless steel reels (made by Hewes) but to expensive and not really needed.
So, when not using the Jobo, I uses stainless steel for 35 or 120.