RWDCelicadude & FWDsux
Remember, the RA Celica's are just a little bit lighter than the MA Supra's, thus the shocks will compress just a little bit more, depending on the setting.
Having had my current set of Illumina's installed since June of last year (I purchased mine from list member Don Lew), I can say that there is a noticeable difference, depending on what setting they are on.
So far, most everyone agree's that the #4 setting feels like the normal HP's when they are brand new. #3 setting feels like the HP's when they are broken in.
The #5 setting feels pretty firm. I only use it if I'm out on a track somewhere (only 1x a year), or if I'm up in the mountains out on the "twisties". The #5 setting to me is more or less okay for daily driving, as long as it's perfectly flat. The minute you go over bumps or small potholes, then the ride gets harsh.
The day after I got my Illumina's installed, I was still messing around with the shock settings, so I decided to pull over & put all 4 corners on the #1 (softest) setting & got back on the freeway. The #1 setting does a very good job of absorbing all of the bumps & whatnot, BUT... I noticed that on the freeway, the car was "floating"... Whatever tiny little bump or expansion joint on the freeway I ran over, I noticed that the car would "slowly" go up & down a little bit... Like as though you were on a boat on the open sea..... Needless to say 15 minutes later when I got home I was feeling a tiny bit SEASICK & NAUSEOUS... That was the last time I put them on the #1 setting. Ask any MKIII owner that has TEMS with the HKS TEMS controller as to how it feels w/ the controller locked at the SOFT setting.... The car "floats"........
For most of my current normal daily driving (because it's currently the crappy weather season & I'm not feeling as frisky when going around the long sweeper freeway ramps), I have them on the #3 setting. Nice compromise between quasi-decent handling & firmness. When it's the summertime (no crappy weather) & I'm feeling more frisky about those freeway ramps, I have them on the #4 setting. Not as much lean, as in the #3 setting.
Adjustments: All you need is a VERY TINY/SMALL flatblade screwdriver. For the front, all you need to do is pop off the rubber cap on top of the strut tower & turn the little dial to the setting that you want w/ the screwdriver. For the rear, just pop off the plastic shock tower cap that is behind the backseats & due the same w/ the screwdriver. You can have all 4 adjusted in about 30 seconds.... None of this crawling around underneath the car & adjusting a dial, or having to take the shocks out & twist them.
Hope this answers your questions.