Chris,
Feel is a funny thing and it is difficult to make blanket statements or recommendations on elements related to feel. That being said, generally we say that the heavier shaft weight will provide a better feel for stronger, faster tempo players. Or, at least in our experience, these types of players prefer the feel of slightly heavier shafts. Now, when you are comparing a 75 gram shaft to an 85 gram shaft, it would take a pretty good sense of feel to notice much difference. Basically, in swing weight terms, 9 grams of shaft weight is equal to one swing weight. It also depends on the weight distribution of the shaft. Two shafts could weight 10 grams different, but one have a lower balance point and one have a higher balance point or be counter balanced. In this case, if the higher balance point shaft is the heavier it might actually feel lighter when swinging. Like I said, feel is a funny thing. Since you stated that have better results when you swing easier and slightly slower, I would have to ask if that is your natural tendency and something you want to do. Is that your natural rythm? If it is, you want to have shafts that provide you the best performance and feel in that state. If you are swinging slower and easier because that is the only way you can get decent results, and it takes a conscious effort to do so, something needs to change. Again, in general, a heavier club feel will tend to slow down tempo and transition and feel better to stronger players. However, a heavier club weight can sacrifice some speed, but for stronger players this is not usually an issue. You want to try to play the lightest overall weight club that still provides you with the feel you want, and can still control. Not sure if this helps, but hopefully offers some guidance.
Britt Lindsey