Nexus 4 is a pure google phone, so yes, it's by far better than the others of its generation, but it is just slightly older now than the newest Samsung S4 / HTC One. Only downside is that it does not support LTE as the newer phones do, and is slightly slower than the newest phones. On the other hand, it is half the price of a Samsung S4 or an HTC One. If you buy it, buy directly from google.com/play for much less than carriers charge.
If you actually plan to use data, I would not get a data plan with less than 3-4 gigs. Yeah, unless you get a retentions offer, it's a rip off. But if you actually want to use it, you need at least that much, preferably 6g. You will probably start watching video like everybody else and then that really racks up the mb's so ideally get a plan where you don't have to worry about it.
If you can wait a few months there is a pure google version of the Samsung Galaxy S4 coming out, and also a pure google HTC One. US launch only initially but good odds they will eventually sell in Canada, or else you could get it delivered to a friend in the US, etc., or if you don't care about LTE, buy the Nexus 4 -- you could actually buy two of them for the cost of an S4.
Technically the Samsung and HTC branded S4 / HTC One are better phones than the Nexus 4, especially if you care about LTE, but I can't stand touchwiz or sense, so if I were you I'd wait for the google branded versions of those phones, if you can wait a few months.
There may be no new Nexus for awhile because Google has not announced any new release of android, and usually a new nexus comes out every time a new android does. This is the longest that Google has ever gone without announcing a new android, presumably because they have now surpassed iPhone in features and don't feel the pressure to rush the next one out. So it may be a bit of a wait if you want a Nexus, for something better than the N4. The pure google S4/One appear to be some sort of compromise, but they don't get the competitive Nexus pricing.