Count me in as another home built unix router guy, pfsense is what I've been using lately.
The cheap stuff just can't handle higher bandwidth with a lot of connections smoothly, especially if you need to do anything complex. If you do VPN at higher speeds its really bad, even a lot of SMB or "pretend" enterprise hardware stumbles here.
You can sometimes find good used real enterprise stuff pretty cheap, but it tends to be noisy rackmount gear, and often it still can't do quite everything a good router distro can.
You can breathe a lot more life into some consumer gear with the custom firmware packages but at a certain point their embedded chips don't have enough grunt. I'm at the point where even an atom cpu is too slow (and thats far quicker than any cheap MIPs stuff) and high speed connections aren't so rare these days (mmmm FIOS) so I'm not alone.
I still use openWRT on various consumer routers for wireless AP duties, its excellent for that.
Nearly dead silent HTPC ver 2.0: i3-4340 w/ Noctua NH-L9i on Z87E-itx inside CM130 elite, fanless PSU, SSD OS drive
SAN shares via 40GbE tunneled over 56Gb infiniband links
microcenter & ebay = severe risks to my wallet