I liked the fact that they gave me my red blood cells back. It made plasma donation seem a lot less invasive than giving blood.
It's much easier on the system, for sure. The limits on how many times per year we can give, in France, are much higher for plasma than for blood (and I'm speaking a 10-fold increase or something like that). I never had troubles when I gave plasma, but I once passed out after giving blood.
The one thing I didn't like about giving plasma, though, was the size of the needle. I was used to those tiny needles when giving blood, so when they brought that big huge thing, I was like "You are NOT going to put THAT thing into MY arm! It's just not gonna FIT!!" But it always did
Unless the nurse was not good at inserting needles, in which case she would explode my good vein and she would have to go looking for another one, and I would sport that huge bruise for an entire week or so :rolli:
Also, I was under the impression that the plasma was going for commercial uses (supposedly it was being used by the pharmaceutical companies as a medium for testing or producing drugs), so it made sense that plasma donation was a commercial transaction as opposed to charitable donation of blood. But that's just what I heard, and that was also back in the early 80s--things might have changed.
Some plasma might be used for commercial uses, but some of it goes to hospitals, for sick people. That's the only authorised use for it in France (since it is donated, it can't be sold), and they collect A LOT of it, so I guess hospitals must have a high need for it.
I did it for FREE, unlike you who are actually SELLING your plasma 
