Furthur: unfortunately the Regular Sentinel MF has been discontinued so ony the Q-Sentinel is available.. But that just means you get an unbreakable more stable version of the sentinel
I like them. They are faster than a ROC and they are more overstable.
Would you say the Q-Sentinal is between the Buzz and a Champ Roc/Z Wasp? That's the one disc that I've yet to find for my bag. Right now, I've got a 2004 SB Roc in that spot, but I'd rather throw something I can get regularly.