Some additional information:

I was just told by my local pool store that the low-speed hp rating for 2-speed pumps is pretty much the same, 1/4 hp, regardless of the high-speed hp rating. This would indicate there is no benefit from going to a 2 hp, 2-speed pump. (The Hayward specs on SuperPumps show a higher gpm at low speed with the higher horsepower units, but the same maximum head regardless of horsepower.)

I have also heard a concern from several sources (including Hayward) that going to a 2 hp pump (or a 3 hp variable speed pump) would risk blowing out some components of my system due to excess pressure.

Is this one of those "You can't get there from here" problems?