Silvertips have changed over the years. The old ones from the late 80s and early 90s were as hot as they say. They came in the white box with orange and red racing stripe and black horse-and-rider logo. The newer silver-colored boxes are weaker, but a step above what the 175gr Silvertip fell to during the mid to late 90s. (Velocities fell to near 1000fps in that time-frame.) A lot of griping on the internet noticed by Winchester got the newest itterations back up into the 1150-1225fps range.
My original Silvertips are guarded quite closely. They're only used when deserving targets appear. We had a soft-body-armor salesman at the range one day showing off his wares and letting officers shoot the vest with their duty guns and whatever ammo they wanted. Lots of 9mms and 45s (this was just before the 40S&W came out), and the vest handled it well. Then, I stepped up with my duty gun at that time, a Glock20 w/ the original HOT Silvertips, and he started to sweat. He even started making excuses before I shot.
Anyway, he had the vest on a mannequine and a chrono set up on a tripod in front of the vest a few feet. I stepped up and fired five rounds. They chronoed between 1265 and 1320 with the average being 1287fps. I was quite happy with Winchester, though I worried what the pressures were on that 1320fps load(!)... BTW, the vest stopped all of them. The silvertip's mouth basically bit into the first five layers of kevlar and then turned inward and the bullet overall "rivetted" into about a .65" slug.