The good thing about a Nexus 4 is that it's not carrier branded, no custom software or crappy UI layers and it's probably going to get software updates earlier (directly from Google) and for a longer time than the android phones with some UI layer on top (Samsung touchwiz, HTC Sense, etc.).
Unless you're gaming on your phone, you probably need a lot less computing power than what the manufacturer is trying to convince you of. You don't need a quad core processor, a 5" display, 2GB of RAM and 32GB storage in a smartphone for almost everything you use it for (3d games, etc. exluded). It's kinda like the PC marketing scam, you don't need a 2000$ quad core 2+GHz CPU with an SSD and 8GB of RAM to edit documents and surf the web :) (an old PC someone is throwing away, a USB stick with Ubuntu on it and you're good to go)
I currently own a ~3 year old HTC Desire, which the manufacturer has abandoned all updates for ages ago, not because it doesn't pack power to run it, but simply because they don't have any incentives to keep updating their old phones and making them better, since that would keep you from buying a new one (planned obsolescence). I put a custom firmware image on it and it's running perfectly. It can easily expand the life expectancy of a smartphone with several years. It's done angry birds, google maps, browsing, facebook, twitter, pictures, sms, calls, etc. all for a cost of ~50USD (bought it used from my former employer) over a span of 3 years.
If you want to get a bit of your money back, sell it and buy an older phone. The previous nexus phones (nexus s and galaxy nexus) are a good choice if you don't want to mess with installing custom firmwares.
With regards to the notifications: awesome choice :) I always feel like I get nothing done and get stressed if my phone beeps all the time, it's so much more relaxing having it being silent unless someone is calling/texting or I'm actively using it.
