Just used a red Personna platinum today. What a smooth shave, no irritation. I think I liked it better than the Astra SP. Going to have to order some of these Personna Labs, I have a feeling i'm going to like them too.
My top two favorite blades are Personna Reds and Med Preps. The Med Preps are simply the smoothest blade I have used.. Feather sharp without the potential for irritation. Just glides across my face. I have yet to try the Labs. I am not sure if an extra steriliztion step is worth any extra $$.. Time will tell.
I've researched and used both and agree with the other users, I like both also but, they are virtualy the same blade. As far as I can see the only difference between the blades is price (meds cost more) and the meds are sterilized for hospital use which I'd imagine is what increases the price.....
I ordered some Lab Blue's because of this thread and they just came in. Was waiting for my Red Personna Platinum to get dull, today I noticed some tugging (shave 3). So tomorrow the Blue is going in. I'm expecting big things.