Nope, I would never buy one. I had to use one about 15 years ago that was furnished by my employer. It was hard to start when cold and there was a loss of power. I believe the company that did the retro said it was 10%. My unscientific believe it was closer to 20%. Have to be very careful when fueling, more than one person ended up with burns from the LPG.
Then there is the safety aspect. We finally got rid of them when one of them went up in flames. Made quit a show, flames thirty to forty feet in the air. The "official" cause turned out to be a supply line leak that was ignited by the hot exhaust. I wish I had a video of it.
Forgot, the darn tank took up about a third of the truck bed. There is also the loss of fuel economy. If you get say 16 mpg on gas, you may get 12 mpg on propane. As already stated I would never buy one. Not sure I would even drive one if it was given to me.
With all that said, it may be possible they have addressed these issues. It is definitely one thing I would check out.