Such a great thread! Thank you both for your detail, it is helping me figure out which first IEM to buy :)
After reading many boards and reviews these 2 are certainly some of the highest quality and lowest priced ($99) IEMs available. I also have been looking at the JVC HA-FXT90, T-PEOS H-100 II, and the Shure SE215. All are $99 (or slightly less). It's quite confusing for a newbie to figure out where to start first.
I was just about to pull the trigger on the Hifiman RE-400's but review after review complained of the low bass. Now I'm no Bass-head. I listen to mostly acoustic, classic rock, & vocals. But still, I do like to hear some bass. So now I'm leaning towards Starfly's recco - which is to stay with the Yamaha. It sounds like either is a good option as they are both similar and up to user preferences. Wish they had a store where I could go try all 5 and then pick for myself!
Anyway, thanks all - you guys rock! pun intended ;-)