Hi rollzone,

You cannot go wrong with any of the Schmidt hubs (nor with the higher end models from Shimano). They are definitely very well made and if you can afford the price, it is the best you can get. Just make sure that you never put grease on the quick release, else the grease may block the "breathing hole". This is clearly stated on their website http://www.nabendynamo.de/index.html (which is for the moment not available in English yet though).

I don't fully understand what you mean with the new Deluxe. For the moment Schmidt sells 4 models : the standard hub for 28 inch wheels, a new hub designed for use in 20 inch wheels, a model for use in foldable bikes (shorter axle) and a model for Cannondale Lefty type of forks.
I guess that what you call Deluxe is the new Son 20 R. The idea behind this hub designed for smaller wheels is that if used on bigger wheels it will turn slower, therefor generating less drag. All hubs that I know of are build to perform as per the German cycling light laws. As a consequence a standard hub has a sweet spot of efficiency around 10mph when laced in a 28 inch wheel. So anyone riding on average faster than this will gain (this means less resistance) by using the Son 20 R. This hub is also lighter (and slightly more expensive). The only disadvantage that you will see when using the 20 R in a 28 inch wheel is that the minimum speed for decent power output will be higher.

I think we have a little misunderstanding on the factor 1.5. What I meant is that when you charge a battery, that a certain amount of the energy that you input through the charger is lost in the charging process. So if you input 1.5 into the charger, you really end up with 1 in your battery. Again some types of batteries are more efficient than others, but the general rule is that you lose part of your input.
This is different from the voltage you need. Apparently (as stated) above, the Iphone needs 5V DC like any USB device. If your charging circuit between your dynamohub and your Iphone is efficient enough, you will not have any issues getting those 5V required to charge your Iphone. I have no personal experience with the pedalpower, but I have looked at their website and info and to me it sounds like their connectors are efficient (if their claims are true).

I also am pretty sure that you will not have any problems generating enough power from your hub to use your Iphone with radio on and any other applications running. Again, i don't know the Iphone, but any dynamo hub generates at intermediate speed close to or slightly over 500ma and that is the maximum that is supposed to be delivered by USB. I would rather be careful at the moment your battery gets close to being full or when going at high speed down hill as I think that then the power from your hub might fry your Iphone. Personally I would be very interested to hear the experiences on this from people who have better electronics skills than I do. Until then I would play it safe and disconnect any sensitive devices in those 2 scenarios.

I hope this is helpful.