Fred,
  Speaking for my non-turbo'd ES (Lycoming IO-540, ~ equivalent hp to a
Continental IO-550) there's NO WAY an normally aspirated ES will go anywhere
near 295 MPH at ANY altitude (unless you're talking groundspeed with a BIG
tailwind).  The service ceiling is listed at 18,000' and it takes a long
time just to get there.  Maybe (and that's a BIG maybe) on a very cold day
at minimal weight, I could coax my plane up to FL250, but it would take a
LONG time and I wouldn't be able to maintain my normal cruise speed of about
190 KTAS (~220 mph).  So the plane you saw had to be either turbo or
supercharged.
  But from the guys I've spoken to who have turbocharged ES's, while FL250
is easily doable, normal cruise up there is in the 225-235 KTAS range, which
still doesn't equate to anywhere near 295 MPH.  The  turbocharged  Columbia
400 specs show the same thing - ceiling FL250, max recommended cruise power
speed 235 KTAS (270 MPH).   That 295 MPH figure you saw translates to 257
KTAS;  I don't think so!  Whoever put that speed on his placard was either
badly mistaken or seriously kidding himself.
  As for stall speed, Lancair's web site lists it at 65 MPH dirty, which is
a pretty good figure.  They also list a 600' takeoff roll at gross weight at
sea level.  From my experience, that's a bit optimistic, but my home airport
is at about 1200', so I don't do many sea level takeoffs.  I also don't
rotate until around 75-80 knots, which means longer takeoff rolls, but
better stall margins.
  Skip Slater
  N540ES