I have used it for some full moons. I didn't like it. This was before I learned about DVCS, so my only real reference was SVN, but for what I did (medium-size business apps, a few years of history) I can't say it felt faster than SVN.

OTOH Perforce had some serious downsides like

  * immature eclipse plugin (would crash eclipse more 
    than once a week, forcing a full reset every.single.time)
  * no Netbeans plugin (back then)
  * the whole idea of having to decide in advance, -while in
    the office or otherwise connected, which files you 
    needed to modify and therefore "check out" -
  * which brings me to the next problem: by default only one 
    person can work at a file at the same time.

YMMW, I see some people liking Perforce, OTOH I see people using Macs for coding as well. (That last part is tongue-in-cheek, yes, I really wish I liked Macs and I recommend everyone to consider them.)