Too heavy as well. I have an HSS SX strat with an "alder" body and Duncan PU. I think it must be from the 'Alderus Cementus' tree variety... It is a real tone suck combo, but plays well. I keep it in hope that I can fix it some day..I was afraid to say this, but unfortunately this could be a possibility.
Bodies that are too light and not dense enough always sounded too unfocused, shallow, and no sustain to me. At least for strats/teles in my experience. I was never able to remedy that with pickups, hardware, or neck changes.