While I would never dictate to RioXingu or anyone else how to run their own tanks - we all have carte blanch to operate as we deem best or desirable for a given set-up. But I cannot resist responding to RX's points:
1. Plenums are inaccessible, as are DSBs, coil denitrators, UV sterilizers, etc. Not everything in all tanks is or for me needs to be immediately accessible.
2. Lift tubes, just like siphon tubes, heaters, etc. are or can be unsightly. concealing such without compromising operational efficiency is just aquascaping, a learnable skill. The powerhead, prefilter, and "lift" (even though downflow) tube are all invisible in the tank mentioned in my last post.
3. Prefiltered RFUG has no gravel-bed "nasties".
4. I have known folks (including Tom Barr/plantbrain) who have successfully kept planted aquaria over UG/RFUG, and to date I am having no issues at all, not have I with veggie filters set over RFUG. Nor have I ever kept any fish which was incompatible with OE-RFUG. I would to hear just why plants and any fish should be incompatible.
5. UG, Canisters, HOBs, and actually W/Ds are all about the same age. Each has its pluses and minuses, so you select what suits your needs for a paricular situation. I use more canisters than anything else, but I also use W/Ds and RFUG and FBF. The only format I don't use is HOB, I think that I can always top their function with alternate techniques and with far less noise - but that is personal choice, I do not consider them outdated, I just prefer other techniques..