Have you put the 3590, ideal, and adapter together and everything sits flush?
I understand that the holes for the adapter and the holder are the same spacing, unlike their other holders, but the spec sheet states 4 total holes. 2 for the holder and 2 for the adapter. At 83* from the holder holes. I also have seen the pic on kingbrite that has them in the same spot, but not what ideal is saying or has told be in conversations. But if it can be "gotten away" with...it's worth it.
TE makes adapters for ledil, but the holders for the 30xx and 35xx line arne adapter compatible yet. But a nice clean look and only 2 holes when using the adapter.
BJB is all in one. They are working a deal with major distributor, so availability should improve.
Looks do matter. Not make or break...but when thinking of a publically available product they matter. Specially thinking of one that's original intentions are for human lighting where ascetics are at a premium. And even in our world, looks matter when getting a light. If using reflectors, ideals gets hidden, but have to deal with more labor of the adapter. Then with lenses...just magnifies their ugly. Many things that don't actually matter, matter to someone. But this particular matter, is not totally superficial. The push in connector of ideal block light. Small, but happens. Other aesthetically pleasing holders actually help in addition to aesthetics...they all have low profile reflectors. And it will give a few µmol bump in the meter. As small and negligible as it is, shows their are better alternatives. Plus the less labor mounting. So that is my stance on ideal, and looks is apart of it.