A lot of the issue with ISP supplied routers and wifi is location. For many people, placing the router in the basement is good for the ISP but bad for wifi. That's due to floors, ducts and wiring blocking signals. It's best to put the router or an access point in a central location in the house.
The HH3000 will have better wifi reception than the HH2000. If it's in a bad location, it still won't be optimal. The Netgear N300 router can probably be configured as an access point. Access points need to be connected with a network cable but they also provide better speeds than a repeater. However, there are much better routers and access points available than the N300 nowadays.
Thank you very much for your suggestion. As working myself in IT/networking for 16 years ago, I am totally agree with your suggestion and you are right that my HH2000 is located in my basement actually, but it's more or less like my best option at first glance because my house is definitely full of high-tech gadget and this is where my IT ROOM is located where I have a W2012R2 server and many NAS storage device here, in addition to my home security system, IP cameras system and of course, my Bell fiber (FTH) entry point is there too.
But the thing is this network setup isn't new as I said and I removed my 5-6 years old Netgear N300 router and put the HH2000 at the exact same place. With the Netgear N300 router I have full (100% signal) coverage of my 2 stories house and also a 80-90% signal coverage of my entire 1 acre lot outside! My house is a modern construction (only 7 years old), all wood structure with no steel ducts or other similar signal blocking structures, this is probably why I had that much coverage with my old Netgear N300 router. But also because of the inclination of the ground where my house is built, my basement is only 33% buried, this allow me to have very large windows in the basement and a lot of natural light and this is also help on signal as well!
To be honest, the point of my question was that I first looked for a fast, easy and "plug and play" way to improve my HH2000 performance in a minute, but it look like it would not very possible or optimal... so here's my plan : I am part of a beta-testing program at Linksys company and they sent me test units of some of their new router once of twice a year and I have in hand right now a Linksys EA7500 router and I think I should be able to run a power circuit and an ethernet cable into the ceiling of my stairwell between my basement and my 1st floor and then wall mount the EA7500 in bridged mode with the HH2000 and then close the WiFi signal on the HH2000 and use it as wired router only... I think this new setup will improve a lot my wireless coverage and overall performance as the EA7500 is one of a hell fast router with HUGE external antenna...
The only thing is that is a pretty hard and complex install considering I have to run wires into closed wall which is a huge job, but the ceiling isn't closed in my IT ROOM who's also located next to my stairwell, this is why I am pretty sure to be able to run wires into the wall betweens.
Sound like a good plan?