There is a "Linux based firmware" from a third party that will load into many routers that will increase security if only because many of the security holes aren't written into the software. But it's more than that, many believe the firmware upgrades a consumer WiFy router to that of at least the level of inexpensive commercial.
Plus, my 310 router was glichy and unreliable till I installed the third party firmware that allowed me to turn the power down. The router has been up for 94 days without a hiccup.
Unfortunately unless the firmwares installation instructions are followed explicitly, especially the hard resets, there is a good chance you'll brick the router.
Do there is that.
On another note, if you live in a house you can put the WiFy router in the basement. Being underground really limits the horizontal range but seems to effect vertical very little.
Plus, when remodeling the house and building the garage I ran lan to strategic walls and to the garage, a run of about 175 feet. The garage has its own WiFy (E1000) with the power turned down to ~ 10 watts.