This morning I loaded two Tech razors with Personas: one with a Med Lab, just got them yesterday, and the other with a Surgical Prep. The Techs are pretty much identical, same 'Pat Off' number on the heads' bases and country of origin are the same--so the variables were, as much as possible, kept to a minimum. My sense was that these blades might be the same. So much for one's sense.
I did two passes with the Med Lab and some pickups--but the shave was not want I had expected or wanted. I couldn't get the stubble/pickups any closer with the Med Lab. Then I picked up the Tech with the Surgical Prep blade. What a difference! The Surgical Prep in the milder-shaving Tech did a great job and picked up everything the Med Lab missed. It was the cleanest shave the Tech has delivered for me thus far: clean, close, and comfortable. Tomorrow I'll do an entire shave with the same Surgical Prep blade. I didn't care for the feel of the Surgical Preps in my Progress--for me the blade felt a bit harsh (I had the Progress set on #3--mine locks on #1).
BigBull had given me some advice: Mild Razor + Mild Blade = Bad Shave; Mild Razor + Sharp Blade = Great Shave. BigBull has had success with the Med Lab blade in a Tech. I know each of us will have different results with various blades in a particular razor. BigBull's suggestion prompted my setting up the Techs with the both Persona blades. So for me, the Surgical Prep worked best in the Tech. However, with this said I'll have to confirm my finding and shave with the Tech/Surgical Prep exclusively tomorrow and see how an entire shave goes.
I would think a Med Lab or Astra SPP might be great is a more efficient razor, like an open comb (on order!), where the razor shaves more efficiently than a milder razor like the Tech--but this speculation on my part--I'll know when I get the OC razors. My thanks to BigBull for his advice--it was spot on.