I agree with you Dan, I think the TH400 is one of the most reliable units you can get. It's simple, strong, tried and true plus there is already tons of knowledge everywhere on how to make them work. For folks who want to go on road trips I can see the desire for some kind of overdrive and that's a matter of choice.
For me personally I like to keep things as simple as possible and od just adds another variable I don't need. I'm not in a hurry these days, I don't need to go 75mph on the highway so a 3:73 or 3:42 is just fine. Most BBlk's are not high rever's, anything lower is questionable anyway unless some tall tires are out back. I have found that the desire to push for more rpm's doesn't always translate to faster times/speeds. If you have truly built a 7000rpm+ motor then that's a different story...JMO