Two years ago I put a pair of Baja Design PAR36 "bulbs" in my C150 and find them just slightly better than incandescents. For the money spent I don't think they're worth it.
For the last few years I've been flying with the flashlight drop-ins in the -6 and like them. Far superior to the Baja's. At night with these lights I've had to land on our grass runway when the PCL box failed and didn't have a problem. There were noise problems initially but that problem has been completely solved.
The drop-ins being now used are these:
http://www.kaidomain.com/p/S025575....Mode-LED-Drop-in-for-TrustFire-3T6-Flashlight
These units, coupled with an adjustable DC-DC converter set to 10.3V, operate noise-free:
http://a.co/eyWVBwd
Noise levels were validated with a spectrum analyzer.
Over the summer we retrofitted these onto a friends RV7 with the stock MR-16 lights in the wingtips. I flew the airplane quite a bit at night before and after and there's a night and day difference (pun intended.)