I have worthington 100s and 85s and I have some Faber 85s (the newer hot dipped galvanized). I personally prefer the worthingtons, especially for single tank diving. They're a little heavier so less weight and their buoyancy doesn't change noticeably. The big thing for me is the Worthys aren't being produced anymore, are very valuable to some of us, and are not losing their value. They will hold their values for years to come. The comment on inferior steel is completely false. I'm assuming that comes from the fact that there is a special bulletin for hydroing worthington tanks. I believe they have to be pre-stretched in order to have an accurate hydro. The negative is that some fire extinguisher hydro places have failed some worthys that shouldn't have failed. I personally am buying as many matched pairs of worthy 85s I can find because I love them.
Forgot to add. If these are the older white 100s from faber they may be the ones that are longer than the worthtingtons and don't have as good buoyancy characteristics. I only buy the hot dipped galvanized fabers. Didn't like the white ones, especially the taller white 100s. I believe those were X7's but can't remember exactly.