Nexus 6 & WiFI Question

Ok so I have been looking at the possibility of getting a newer router the one I have came from my isp provider and is a Netgear N150 model router. I know the Nexus 6 supports The new AC standard but it's the only device I have that can even use the AC network standard so it's not economical for me to do an AC router so im sticking with the N network standard since that's what everything I have supports.

So my question basically all sums up to if I buy an N300 router and use it will it increase my wifi speeds... I know it is all about throughput and some say expect half the label speed still with an N 300 the half speed would be 150Mbps (megabits) which is a still faster than 75Mbps.

I also know the speed gets better on the 40mhz (megahertz) channel width than the 20mhz channel. Which brings into question does the Nexus 6 support the 40mhz channel width therefore allowing the maximum possible wifi throughput.... Of the theoretical 300Mbps?

I look forward to reading anyone's ideas and or explanations .... If by chance I worded something incorrectly forgive me I have been looking at info for a few days trying to figure out if getting a new router is worth it and have a lot scrambled up in my head right now. But I hope the way i worded it helps u know what I'm trying to say