I have a couple on Oncidiums given to me that were pretty spotted (little black spots on the leaves). One is struggling, but may revive with more light and in S/H, it seems happier. That one blooms like the pictures here. The other looks like a purplish version of a Twinkle, it grows and blooms freely if I keep it watered enough. It's new leaves are a lot happier than the old ones - I have more air flow for it and I moved it into the Cattleya light and out from under the artificial lights. Its not yet in S/H but will be when it has a break in blooming. I have a "Sharry Baby" that is growing better in S/H than it was in regular media, less accordion leaves, plumper p-bulbs. It wasn't blooming when I got it from a small store that was closing, it was a wee bit sad, but looks good now. I have a Wilsonara Pacific Panache 'Fireside Fever' that I got at a box store last spring (with a label!), nice vigorous plant, I can't wait to see it bloom. It has 4 new growths on the way, it seems to like S/H too. Then there is the Miltassia Shelob (don't know if its a named clone or not), which has struggled with humidity and water in my dry climate - it seems to be really happy in the S/H and has two new growths. So, so far I've been able to keep the Oncidium types alive, and bloom the easy ones... now I am hoping for good results with the fancier ones.

I do get spots still on the leaves, I treat with fungicide sometimes or insecticidal soaps (not completely sure what causes the spotting, if it gets really bad, I will gradually lose the leaf). I treated with Neem once and didn't know to keep them out of the sun and burned a few leaves on my learning curve. However the rest of the plant really improved after that treatment.

I guess I'm rambling in hopes it might help someone grow these!