ASSUMING the poll on the Iconbar could be considered accurate in any way and looking at the 'latest' incarnations of RISC OS
27% use Select most regularly vs 20% using RO5.
Considering RO5 is less than two years old, and requires you to buy a new machine, whereas Select is more than three years old and requires no new hardware, I would have thought that many more would be using Select.
Also interesting that RO4 = 29% (a fiver year old OS) and still 15% using RO3.5-7 (10-8 year old OS). I'd say that the Iyonix/RO 5 has done remarkably well.
On this poll you would most likely only lose the interest of 29% and not 80% as you suggested.
As many Select like features are available for RO5 (PhotoFiler and CDROMFS now 32bit share and freeware utilities provide other features) it would be relatively easy to ship a version of RO5 with most of the visible Select features implemented.