We have bred three of them, all with our Star status Friesian stallion. All 3 are stunning! Dishy faces, good bone, lots of hair with floatly animated movement. Two of them were very calm (yet forward) and fearless. One was a bit on the "hot" side and took special handling.
When I accompanied my friend and her 3 year old mare to the trainer last year, we found that they had a pair of arabos in training for combined driving. Nice horses, they look mostly Friesian, but with a bit more refinement in the head and legs. The trainer mentioned that there were some differences working with them vs purebred Friesians: mostly that they have endurance in spades and were more sensitive. Sadly, I didn't take any photos of them that day.
I've seen a few for sale and I've always liked what I saw. The resulting progeny always seems to retain extreme Friesian type, but with a bit more refinement to make them a little lighter and perhaps a bit sportier. I don't think I've seen one yet that wasn't very correct and good in the showring. I think it's a great cross for someone prefering the heavier type but with a little more energy and a little sportier for doing several different disciplines.