1.) 16GB
2. Speaker is on the weaker side. I picked a really loud, obnoxious ring tone to be sure I don't miss a call. (it's whatever the 'old school' 'classic' phone tone is)
2.) No detectable yellow tint, as far as I can tell. I'm not sure if I have a phone from a newer batch, or what. I didn't have to do that huge update that many early buyers had to do, either.
3.) Reception seems to be a little on the weak end. My wife is getting 4 bars (or dots) on her phone and my phone is only getting one bar. She was previously on Virgin (Sprint) and I was on AT&T - now we're both on T-Mobile. My previous phone was an iPhone 4, and I usually got 2-3 dots (bars), so I'm a little suspicious of what's going on. I'm going to dig in to see where my nearest tower is.
My wife was super impressed with the Moto X features based on the website, but she didn't want to wait for it to ship from Motorola. I agree that the X has some pretty cool features, and the fact that it runs pretty close to stock Android is an awesome plus.
Of course, I do have to say that my experiences with the N5 echo everyone else's - the camera is great when the subject is non-moving; otherwise, the focus is woefully slow and inadequate. If Google really is working on a software fix, that would be pretty great.
Overall, I think that you can't go wrong with either the X or the N5. I know I'm incredibly happy with my N5 because my previous phone was a tiny screened, single core iPhone 4. It's been an absolute joy to consume media over the past couple of days in comparison with my old phone.
Good luck!
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You definitely can, but you have to enable it in the 'security' tab in settings, first.