I try and keep the same ph targets as you do.
Soil, unlike hydro, takes longer to respond, but is more forgiving, IMHO. I personally believe that your soil will take on the ph of the applied nutes. That said, I'm not an expert but do believe that if your let your soil get too dry, the evaporation process creates un-necessary salts and other buildups, which will change the ph.
If you use a clay pot_which I prefer_it is harder to keep the roots warm, due to the evaporative characteristics of clay vs none in plastic, but the clay has a tendency to 'wick' the salts out of the soil and into the clay. If this is true, then the soil benefits which helps the plant. I'm beginning to believe the best scenario is a clay plot with one of the CFL's actually touching the pot to transfer a bit of the heat to pot, thereby keeping the roots warm.
Like you, I'm into the digital toys. How kewl are they?
. I'm getting a new digital thermometer with the waterproof probe_from fish store_this coming Tues. Can't wait
Keep the ph @ 6.3 ~ 6.5, I don't think you can go wrong with that setting.