As David said, the only difference is the length. Cutting a roll of 220 in half will give you plenty of practice film about the length of 120. When loading SS, I find it easier not to use any of the various little clips on the various SS reels I have. Just hold the film in place with your index finger for (about) the first eight of a turn or so, and the film will hold itself in place, thus minimizing chances of misfeeding.
I hear all the good things about Hewes reels here on APUG and trust that for most mortals they are superior in their ease of loading. For ham-handed me, I find them (in 35mm) no different than the various SS reels I have accumulated over the years.
With SS, once you acquire the knack, it goes pretty smoothly. The knack, and how to get it, is a matter of practice. I knew some old lab rats who just could not load SS Nikor reels--which are (were) the best there were at one time. BTW, Nikor was an American company, making and selling SS reels and tanks when Nippon Kogaku was unknown on the American market. Nikor was sold by Burleigh Brooks, Honeywell, among others and had nothing to do with Nikon. FWIW.