Those bottom times might be accurate diving off a chart. With computers it's a whole different ball game. Most my dives go down to 80-100ft and last around 30-40 minutes. Heck, my last one was down to 130ft, I was under for 30 minutes, no decompression stop needed (I did do a 3 minute "safety stop," that might be what you were referring too). Oh, the scenery was pretty nice down there too, colors were washed out into the blue spectrum, but besides reds you could still tell what the colors were.
+1, I have no issues taking my reps down diving with me. My cheap POrikaa has actually been the deepest out of all my watches.
But anyways back OT, a DSSD should have no problems diving down within recreational limits <130ft. Also, if you're a brand new diver, chances are you won't go below 60-80ft. The main issue though as people have pointed out is that most reps have little to no QC when it comes to seals and caseback tightening. Sure, most of them have everything, but you never know until you look. So unless you take it apart, you'll just have to trust it's put together right.