Yes, I know atleast there (TRD) regualar performance springs are made by Eibach, hence the 1" or less of lowering. But, they also made a harder to find TRD race spring for the AW11 that dropped almost 2".
I wonder how much stock springs can really sag, 1" full inch? I don' know about that.
i enjoy my 'regular' TRD progressive rate springs. they lowered the car as they adverstised. i also feel that my handling is NOT underrated or anything. i do pretty well during track events and autocrosses and during 'spirited' driving.
i have the ST's and the car looks great...the ride is a bit harsh...but its not that bad once you get used to it..and as for the good luck finding them i called nopi and i got them like 3 days later do id try them first...
I got my ST springs and also the Cusco rear strut bar - the special one for the SC - from the old 6deep.com that went out of business. I guess I got mine right before they became hard to get - just lucky.