I know this doesn't address not being able to get ahold of Jeff when your headlight has been trashed by a rock, but I'm going to throw in my experiences with his headlights as another data point.
I bought HIDs for my wagon from Jeff just over 6 years ago (47K miles) and have been pretty happy with them. The housings have been great. However I've chosen to replace (see below for technology changes) or had to replace the bulbs, ballasts, igniters and relay harness - some of those more than once. When any of those failed and were under warranty, I never had an issue with getting a replacement from Jeff, but it is annoying when one or both of your headlights don't work and you can't just go down to AutoZone to get a replacement bulb. When you choose to install aftermarket HID headlights, just be aware that they're unlikely to be as reliable as the factory headlights. It's not just wires and bulbs; it's now wires, extra wires, even more wires, relay harness, ballasts, igniters and bulbs. I think all the electronics are generic parts from China, but for the price that's ok. I don't think anyone should expect "German reliability" if you're paying China prices. If you're going on a road trip, it's probably worth packing an extra ballast, igniter and bulb. It would be a good option if you could buy headlights with 3 each of all the electronics because, at least in my experience, they're all going to fail within a few years, and it really limits you when you don't have working headlights.
I'm not sure if the technology changed every couple years or if Jeff maybe didn't make quite the best choices when he first started out, but the ballasts changed from 55W DC to 35W AC and changed brands at least a couple times. The relay harness originally was a single point of failure, so if it failed, you'd lose both headlights. (This happened to me...while on a trip...at dusk) The bulbs I think originally had wires attached, then changed to socketed bulbs, which are a bit easier to replace if one burns out, but harder to find a replacement as they're not as common. Some of the problems I had may just have been because I was an early adopter. The newest generation of Jeff's components may well be more reliable than what I originally bought.
Having said all that, I don't regret buying HIDs from Jeff. I'm getting older and it's a lot easier to see at night with them. You just need to carry some spares and know that if something catastrophic happens to one headlight, you're probably not going to be able to get a replacement super fast.