I cant see much point with the depth guage, and the altimeter seems to be too fiddly. You would have to retune it all the time when the barometric pressure changes.

My SPF40 has the rubber strap, and I find it a little uncomfortable. I was hoping that the Titanium band would be more comfortable. My wrist changes size through out the day as well and I find the metal link bands suit me better after I have initially set them up.