I've never had a Super Action, but I'm sure the neck profile is that of the early MK VI. IMO, these necks just don't blow like the later improved MK VI neck, so that's a possibility since you're comparing it to the VI. But most likely you're experiencing simply characteristics of that particular saxophone that influence resistance, like small leaks, key opening heights, pad types/materials/tone boosters and possibly dent repairs, particularly in the neck, which can result in incorrect profile/dimensions in the neck. I believe that a sax that requires a perfect reed in order to get good results is sucking the power out of your playing. Any tenor sax should be easy-blowing and 'buttery', which enables you to use a slightly harder reed to get more volume, tone and 'urgency' out of it. If you have to use a 'buzzier' reed because the horn is sucking your sound, then you have to fix that. The horn needs to be closely examined. A lot could be, and usually is, wrong with a sax that old - or any sax, really. If you can't do repair work yourself, you might want to find a tech to look it over for leaks and any keywork problems. Look closely at the neck to see if you can detect any abnormalities. Assuming everything else is basically okay, try a Selmer Series III neck on it, or really any new neck in the MK VI profile. Here's an example of one common thing that could be your whole problem - the pads might have build-up in the seating rings. This basically produces small leaks at every pad and makes the sax resistant, or 'reed-needy'. This build-up can be nearly impossible to remove and usually requires a pad job and tone hole cleanup/leveling.