If you decide to do some tests to see how Uber rendering compares does that then mean the glass objects will render, allowing light rays through also allowing caustics?

I think transparency management is an other problem, but now that I finished DAE/Collada support in current beta version, I'm going to work on it.
I've made some tests with caustics too, but it slows down rendering process too much (for more information about caustics please read this nice article). I feel caustics are probably nice to render one or two transparent objects but not a whole scene with many potential transparent objects.

I would be quite happy to beta test Uber rendering for you.

Thank you. Your help will be precious since rendering process is often lengthy and I don't always think to test special camera locations like you did. [;)]

If Uber shader doesn't work well or is too slow, could you use the shaders you were using before but insert a Phong shader in the middle?

I never tried using multiple shaders per object. I'll have to test that. Thank you for the idea! [:)]