As you say it's all about experiences and in my experience with 12 years cleaning and restoring I've never found the need to use honing powders in conjunction with a quality floor cleaner, expecially something so basic as a ceramic or porcelain tile.
I think your find the masses will say the same, the masses being the manufacturers of specilaist cleaning and sealing products, otherwise as a manufacturer we would produce these simple powders, as you know the majority of manufacuters in the UK and Eurpoe don't offer these powders.
I am confident your process works very well, but as you know there are many products and processes that also work very well. We have our own likes and dislikes, I'm not a fan and don't think they are as necessary to use as you do.
For the forum members who like using honing powders try Simba Products (01709 770801) I've been told by many professional restoration companies that there products work very well.
http://www.simbamaterials.co.uk/prod02.htm