I have never used any kind of Mini35 converter or P+S Technick or Letus, but I have seen footage from them that looks very good and am interested... I have an XL2...

What is the difference in using a Mini35 adapter with Photo lenses vs. using an XL2 or XLH1 with the Canon EF lens adapter ring and then using Canon photo lenses on that? Does this not accomplish the same thing? -
And for cheaper?

I am guessing there is some advantage these image converters do that Im just not understanding...

It is all about the available field or angle of view for a given focal length permitted by different mage formats.

Typical MiniDV CCDs are 1/3" or the effective pixel area just under 8mm wide approx. Depth of field is very deep, great for forgetting about the need to focus but very limiting when one wants to get creative with shallow depth-of-field effects.

35mm motion picture film frame is 24mm wide. (frame is across film width)

35mm still-camera film frame is 36mm wide. (frame is oriented along the film length.

Shallower depth-of-field for the same field of view can be had with 35mm film formats, a useful creative tool for making a subject stand out from a background.

Groundglass diffusion tends to soften the sharp-edgedness of video imaging and confers a more pleasing apparent contrast effect.

have a look at the alternative imaging forums tyson or go to my website and look up 35mm shootout for some info