The 10D will be better if you live in a hilly area.
It is incorrect to say the 5i's IGH is relatively maintenance free. It still uses a cable to shift, and the bike still has a chain; those two things need the same maintenance as the 10D. The only difference with the 5i is that the gears are inside the hub so that bit is shielded from dirt. Trek/Electra also uses the same frame between the two models, meaning they had to add a chain tensioner to the 5i, which can be damaged as easily as a derailleur if the bike gets knocked over.
What would have made the 5i more maintenance-free is if it had a Gates carbon belt instead of a chain.
Lastly, an IGH makes repairing a flat tire more difficult. Unlike a derailleur bike where the quick release is opened and the wheel comes out, with the IGH the gear cable must be disconnected and the axle nuts loosened (with a wrench). Have I mentioned that disconnecting and reconnecting the cable on Shimano IGH's is fiddly? Well, it is.