I think either would be a good choice for what you're wanting to do - both the century and the daily 25-30 miles. At this point, you're not going to see a big difference between the two speed-wise. I can zip around for short rides on my Ruby as well as someone of a similar ability can on an Amira, so you're not sacrificing either speed or endurance, at least for what you're wanting to do.

Ride them both, and decide which one you like to ride better, because they're both good choices. Have fun!