I dove my new regulator tonight for the first time and it was quite nice. I can confirm that it is all metal except of course for the parts you would expect not to be metal such as the diaphragms and mouthpiece.
Yes it honks a bit at the surface but that goes away as soon as you get under any water. I found the pre dive and breathing adjustment controls easy to find and manipulate with my dry gloves on. I liked the fact they are on one post as it kinda simplifies the finding and adjusting. Regardless of how I found myself in the water, prone or supine, vertical head down and in a roll breathing was as expected, good.
They say it is only a little bit smaller than the S600, but I think that measurement includes the torx screw points as it looks noticably smaller. But for my hands it is a great size.
Another thing I really liked was dry mouth at least on this dive was not an issue. I have always dived a rental reg before, the R195 Scubapro and I found my mouth would get a bit dry during a dive, never enough to be a worry but its nice to maybe be able to put that discomfort behind me. I am out on the boat to do a couple dives on Friday going to do a deep dive for some cloud sponges and am certain I will continue to be impressed with this little beauty.