I have had a Dtech with no troubles for 3 years. I purcahsed a Dtech recently as a spare. I think its a viable option. PMDcable.com has been having a lot of warranty replacements with them, but I think that could be from the fact that there are more of them, and the vehicles they are going into. If Stanadynes had been in there, they probably would have failed too.
My advice, Dont get it too hot, dont get it too cold, make sure the PMD metal mounting surface is grounded (meaning no thermal pads and ground your heatsink), and don't jump start your truck unless you have to. Slow charge dead batteries and for sure don't use 50+ amp jump starters, using another idling vehicle if necessary, or even leave the 2-6 amp slow charger on while cranking. I think they are sensitive to electrical surges, and people often times have some battery issues, or an alternator problem, and months later have a failing PMD, so they dont think they are related. When you zap stuff, it doesnt always fail on the spot, the degradation process begins and gets worse with use.