Wifi and ethernet on two Netgear CG3100

What i want is best possible wifi coverage as well as being able to easier connect multiple devices in different locations with ethernet cables, and just the one CG3100 simply didn't cut it. Luckily i had another CG3100 laying around so i now have wifi from both of them and i'm also able to connect devices with ethernet cable to the closest one instead of having long cables running everywhere.

First CG3100 is being used as modem connected to the wall through the WAN port. It is also used for wifi and ethernet.
Second CG3100 is used for wifi and ethernet and is connected from a LAN port on the first one to a LAN port on this one.

We're paying for 100/10 connection and on ethernet from both CG3100 i get 111,5mbit down and 12,5mbit up.
On wifi i'm getting about half the download speed, and i understand that this is because they're old and can't deliver higher wifi speeds. However on the first one it tops out at around 54mbit down while on the second one it never seems to get higher than 46mbit down, is there any possible explanation to this?

Everything has been working perfectly ever since i got it up and running maybe three months ago except that my phone sometimes starts roaming forth and back without any apparant reason which sometimes makes me have to update webpages/youtube videos to get them to load (At least i think the roaming is the reason that it happens). Any thoughts or suggestions about this?

Lastly i'm wondering wether there are any software changes i should make to either of the CG3100's or if it's already properly set up (See screen shots below). If i should change anything, why should i, and what happens from doing so?

http://i.imgur.com/tMggx3H.png
http://i.imgur.com/uFDyKb3.png
http://i.imgur.com/gX6ezZJ.png
http://i.imgur.com/8QoWHII.png
http://i.imgur.com/VkZfNlG.png