Is any software really bug free? Most likely not, but compared to DD-WRT it is bug free. :P
Additionally I’m not sure why you think Broadcom has the best performance. There are plenty of devices out there and they don’t need to be Broadcom to be good.
Because Broadcom doesn’t play fair, they have hacks that go behind the published WIFI standards and get it go a few megabytes/second faster and/or improve the range a bit. And to take advantage of those feature both your AP and client must be Broadcom.
Not saying that MediaTek isn’t good, because it is, I use a ton of MediaTek devices and they’re all great.