[Nexus 5 Q&A, Help & Troubleshooting] GSLEON3:
A device with a body made of metal alloys is ALWAYS going to feel warmer during strenuous operation than a device body fabricated out of plastic or composite materials. Mostly, that is a good thing, for both the device internals & battery life. Metal is a better conductor than plastic & also has a lower "R" value. These factors serve to allow the metallic device to better dissipate the energy transferred to heat, away from the device & into the cooler ambient air. While the exterior of the device may be warmer, the interior components are often cooler & they definitely cool down faster when they do heat up than they would in a plastic bodied device.

As to the question itself. The Nexus 5 can & does heat up like any other device & how noticeable it is, depends on how you use the device. Again, you will not notice the heat as much, but the internals of the device will. The Nexus 5 itself is a worthy device, tho I am using mine less & less as I find more to like about my new HTC M8. I am certain that you could probably find the Nexus 5 online for nearly any carrier for free, if not close. While I am a Nexus 5 fan, you just don't get the same quality in the Nexus line that you do with other flagship devices. GPS drift can be horrible on the Nexus 5 & I don't mean just from my experiences. I belong to a large Ingress group, many of whom use the Nexus 5, nearly all of them suffer from horrible GPS drift frequently. The M8 on the other hand, has been rock steady, gives me better AT&T 4G LTE signal & just all around rocks. HTC isn't providing a free, one time, 6 month screen replacement garuntee because the device is haphazardly thrown together partially based on the lowest bidder to mee the specification outlined by Google. Also, just know the the Nexus 5 battery is mediocre at best & without a lot of trial & error (& some help from Flar2's ElementalX) you are lucky to see 3 & 1/2 hours of screen on time. I was able to get it out to 5 & 1/2 hours, but again, it took a lot of tinkering & thankfully there was a solid kernel with good source available to build from.

One last thing. While you will benefit from regular software updates (which HTC has also made a part of their HTC Advantage program, not too mention they took Google's queue & started releasing modular updates in the form of Play Store service update packs) remember that in 6 months or so, the Nexus 6 will be out. At that time, based on Google's revised support schedule, you could potentially stop seeing updates on the Nexus 5 about 6 months after release. Now I don't expect that to happen, however, if the reports are true, it could, since it sounds like Google is wanting to go away from the Nexus program & stick primarily to GPe devices.

I don't think you'll be disappointed with the N5, but it just isn't the same type of quality as the HTC M7 or M8. Plus, now that there are GPE devices for both HTC models, converting to a GPe device that benefits from a Nexus-like update program is a simple thing.

At any rate, just some food for thought. I loved my N5, but I wouldn't buy it again today. At the end of last year, or even in January or February 2014, maybe, but not now. While you cannot go wrong with the QC SnapDragon 800, the Nexus 5 is primarily lower binned chips & the new 801 takes the same performance & enhances battery life. With only an additional 300mah, right out of the box I was getting nearly 6 hours of screen on time from the M8.