Just my opinion based on moderate amounts of experience, but unless you are way underpitching or fermenting way too hot, there is no reason to let your beer sit in secondary or even primary for 4 weeks. I don't even understand how it's possible to let beer sit around for 8 weeks before bottling or kegging unless it's a really big beer. I usually do about a 10 day primary and then it's off to dry hops and cold crash for another 7 days. This is with up to 1.070 gravity beers and I have great results with no off flavors. Without getting into the big secondary debate, in my opinion there is no reason to sit on beer that long before carbonating unless its flawed to begin with.
Also, if you had gushers after 8 weeks of fermenting and a few more weeks of bottle conditioning, then you either didn't take any gravity readings before bottling, or you put in too much priming sugar, or you caught some kind of infection.
