Chronarch MGL has a plastic line guide pawl with a metal worm shaft and it's fine, not sure yet, but most likely newer Shimano reels could have metal guide pawl and plastic worm shaft nothing and nothing wrong with a polymer worm shaft IMO. 18 Bantam has the first Gen silent tune, 22 Bantam has the second gen silent tune, Infinity drive and MGL 3 spool and yes, the 22 Bantam is over all better than the 18 Bantam. I still have two 18 Bantam and I still love both.