I have two of those Bessey (EKT-55) clamps, but have only used them when glueing biscuited lippings onto birch ply. They are surprisingly good at clamping, partly because they have a (silicone?) rubber pad under each of the gripping jaws which I found reasonably slip-proof. I found that, if I wanted them to grip very firmly, I needed to press relatively hard on the handle to engage the gripping pads well, before the edging part of the clamp's screw operates. I know that last sentence sounds a bit confusing but, they have an interesting dual concentric screw mechanism which supports the "one-handed" claim.
I have not tried these on MFC (which, as an amateur, I can choose to only use "under protest"!)
The body is made from some sort of alloy (I suspect a magnesium alloy from its weight) so they are relatively lightweight and this tends to NOT distort the work.
It is worthwhile shopping around for "best price" because Bessey prices do seem to vary a lot.
I also have two of the VERY heavy duty edge clamps (KT 8-3) which are very strong and also very heavy - so will tend to make work sag under the weight.
Both of these have done a competent job for me (when I remember to use the right one for the job!)
In contrast I also have the dual screw units (KT 5-2) which fit onto the Bessey F-clamps, but for me these tended to make the F-clamp pull out of its plastic boot before any serious clamping force is produced, so they are more of a dust-gathering curiosity for me at present. I will probably find a good use for them some time, but maybe not so soon.
The Rutlands one looks like one made by "Gross-Stabil" (which I have not used), but it may be a copy carrying their "Dakota" brand.
Simon