It uses a spherical core seat - like the V16, V32, etc. The second stage is not all metal like the abyss... but the performance should be close. As far as worth the money - they were discontinued about 3 years ago... I bought a ton of them and was selling them for $499... so it's only about $50 more than an abyss - and you get Titanium. We no longer have those... maybe one kickig around, but we got in a boat load of the oceanic titanium regs now at sub 5 bills.
People ask me about Titanium all the time. I tell them - titanium is great. That reg will not corrode so it could last 1000 years. And the brass version... probably only 200. So it depends on 3 issues. 1, how far down the family tree to you want to pass it, 2 do you need the light weight because you are backpacking your gear into remote locals, and most importantly 3, will your friends be really impressed that you have a titanium reg.
Oh, I guess I could add 4. Are you a moron that drops your reg into rinse buckets without the dust cap on. In that case, the Oceanic DVT or Titanuim will help you out.