I have ran them for quite a few years. One I run the hell out of, no issues, no cracks. They have been trouble free engines. The MPG's aren't all that great., I would prefer the 4bd2t, but have read issues about cracking heads.
I will say I found since buying a 7500 lb DI Cummins truck that it gets the same MPG's as the Isuzu's and almost as good as 2H and 3B Landcruisers I've had with LOTS more power.