<p>First, there are a ton of similar queries already online. Here are a couple:<br>
http://www.photo.net/medium-format-photography-forum/00GJa4<br>
http://www.getdpi.com/forum/medium-format-systems-and-digital-backs/54003-hasselblad-cf-50mm-vs-cfi-50mm-lens.html<br>
And some info / advice:<br>
For optimum quality across the field at all apertures / distances, get one of the FLE versions (either CF FLE or CFi FLE). FLE stands for floating lens element. It's a second adjustment you make on the lens, based on your focusing distance, after you've dialed in focus. Yes, it makes a difference in sharpness vs the earlier C and CF versions you've listed (without FLE). <br>
Between the CF and CFi versions, there is no difference in the optical formula. The differences are mostly cosmetic. I do prefer the look and feel of the CFi lenses, but it might not be worth the difference in cost to you. I've had the CF FLE and the CFi FLE, and they both performed equally well. That is, beautifully at all apertures. <br>
My body is a 203FE, and I prefer the 2.8 FE version for the extra stop and the electronic contact between body and lens. It's sharp at all apertures, and there's not the extra FLE ring to adjust (that lens element adjusts automatically in this lens). If you're shooting fast in changing light or changing framing, it's quite useful to be able to use Aperture Priority and have the camera automatically adjust the aperture. The other lenses you list won't do that. </p>