I have not tried double red cell donation. It takes about 30 minute more than a whole blood donation. They can take twice as many red blood cells, but then you have to wait twice as long between donations. So you kinda end up at the same place.
There is supposedly an advantage. According to the Red Cross web site "With all of your platelets and plasma returned to you along with some saline, you don't lose the liquid portion of your blood and may feel more hydrated after your donation."
So if you think this would help you, try a double red cell. I don't seem to notice the missing plasma and platelets ... the body replaces the plasma in like one day so it's no big deal (for me at least).
Perhaps someone can clarify ... for a double red cell donation - do they need to insert more than one needle (one for the blood and a "return" line for the plasma). This is not a deal breaker, but I try to minimize those vein punctures.
That's my plan. I don't think I will have any trouble with the double red. Shouldn't have the blood pressure drop like a full donation.