While The Verge has nicely explained why the Nexus 4 comes without LTE, it stops short on explaining why LTE is not really a critical feature.
Actually LTE is a critical feature, but it's critical to Verizon and Sprint, not directly their consumers.
LTE has at the current moment only one thing going for it, and a long list of drawbacks. LTE provides, especially for the non-HSPA+ networks bandwidth, by using better technology and additional frequencies. Hence non-HSPA+ networks need consumers to use LTE handsets because their non-LTE handsets are forced on an overloaded network.
Tests suggest, that given comparable coverage, the difference between a good HSPA+ network and LTE are mostly the smoothness of operation: LTE having no (or not overly many) users, have always enough bandwidth to deliver say 20-30mbit/s, while HSPA+ has a tendency to be slightly more volatile bandwidth, as it's to be expected with a network that has shared bandwidth and active users.
The issue here is, that this benefit of LTE will go away with time when the network gets more users, so it's again only Verizon/Sprint with their proprietary pre-LTE networks that are way over their capacity. HSPA+ while no LTE, has enough capacity to keep the users happily youtubing on their mobiles without issues.
Now LTE has a number of drawbacks:
- power usage: LTE is new technology, so it does use more battery juice, as has UMTS in the past. Personally, I've just killing the habit of switching my mobile to 2G-mode only to preserve battery, my current Nexus seems to handle UMTS well enough that the GSM power benefits are rarely relevant.
- VoLTE. MetroPCS has started to deploy VoLTE just in August, and till that works well enough, probably somewhere next year, LTE is a pure data network, with no support for typical phone functionality, e.g. phone calls. The ugly CSFB fallback solution where devices fall back to non-LTE networks adds a couple of seconds delay, plus leaves you potentially unreachable while being online (in all the places that have LTE coverage but no pre-LTE coverage). It's a hack, and an ugly one at that.
- LTE without flat fees is a non-starter. LTE can roughly pull 1GB per minute. Without a flat fee it's kind of like driving a Hummer while gas is rationed. Add to this the fact that data usage is hard to measure and very hard to correctly assess by lay persons. Combined this gives a situation where depending on your contract you pay quite hefty fees or are throttled to dialup modem speeds. Not good.
- LTE is a frequency chaos. Building a HSPA+ mobile that works globally (the only country without a GSM network that comes to mind would be Japan, West Sahara and a couple tiny islands) is comparatively simple. LTE adds 7 frequency bands on top of GSM (4 bands) and UMTS (5 bands), which leads to situations where selecting the right mix of bands is hard (e.g. the iPhone 5 can do LTE in Europe on exactly 2 LTE networks, out of roughly 70 LTE networks. So LTE makes a phone meant to work globally quite a bit complicated, with minor relevancy to the majority of users. Some manufacturers do the hassle dance to serve Sprint and Verizon, but for the time being LTE is irrelevant to the rest of the world.
So if you live in a place without reasonable GSM/UMTS coverage, you'll probably need a LTE device. If you're in a place with reasonable HSPA+ coverage, one might want to consider switching to an operator that operates with standard technology.