I was using Flitz on the bike I am presently rehabbing, because I have been very strictly rationing my remaining stash of Quick-Glo. It works, but was taking a LOT longer than Quick-Glo. I finally decided to stop burning so much time, and got into my stash. The difference in performance is remarkable.
Having said that, I might be a little hesitant to use either product on show quality chrome, as they both have some amount of abrasive content. But for all of the oxidized metals I rehab, I love Quick-Glo.
It’s been ages since I’ve used Simichrome, so I can’t offer informed feedback about how it compares.