Interesting comment. I have a number of MR16 bulbs in my house that were previously halogen and are now mostly LED. They are a near constant source of frustration with bulbs burning out way too soon, some with what seems like wiring issues, a mix of incompatible switches, etc.
Curious to hear what acceptable solution you derived?
Good dimmable LED bulbs from quality manufacturers like Philips dim very well with many incandescent (leading edge) dimmers. Usually these bulbs are larger and have space in the base for a driver circuit that derives a brightness signal from the waveform rather than passing through the chopped current.
Smaller bulbs with no built-in driver are much more suited to dimming using a trailing edge dimmer or dedicated LED driver. These strobe like mad on a traditional dimmer switch but may benefit from having a single incandescent bulb on the same circuit to round off the waveform a bit.
For one difficult circuit I put a 5w ceramic resistor in parallel with the lighting to smooth out the dimming response between two different fixtures.
Are they low-voltage lamps? (usually have a GU5.3 base). If they are powered by old transformers intended for halogen lamps it might be worth changing the transformers to ones meant for LEDs.
Incidentally if there are dimmer switches in the circuits then those might have to be changed too.
Curious to hear what acceptable solution you derived?