Hi nizx. Customer service is a hurting dog these days, mostly irrespective of the class of product you're buying into; RMAs, end-user support, etc... As a service provider myself, it has become quite a challenge to provide quality primary care sustainably, as proven by just the stories I've heard in the last year alone, which would leave most people somewhere between dumbstruck, laughing and crying...
First option, as others have suggested, is jumping right back into a big-box products. The chances of 2 lemons in a row is very low *knock on wood*. As long as said unit and whatever firmware can route 200Mbps full-duplex with all desired services/features turned on, and do so below a temperature hot enough to melt the tiles off the space shuttle, you should be just fine.
Second option are the value enterprise-ish products, largely absent of much support from the OEM -- ie. Ubiquiti and MikroTik. Not much more needs to be said. If you can hack it with this stuff, then the thread doesn't need to go much further.
Then there are some SMB products that for a slightly higher purchase price tend to offer better reliability and way better support, but you'll have to give up some bleeding-edge features and a fair degree of "all-in-one"-ness, depending upon the vendor. For what it's worth, the integrated appliance vendors seems to do pretty well here -- Peplink, Zyxel, Cyberroam, etc. You'd be investing a bit more for a bit "less" on the product side, but without saying that the support will blow the socks off the big-box brands, well, I would say it.
Best of luck.
