If mirror slap is an issue you're using the wrong camera.
High quality horizontal shutter SLR's like the OM's or Canon New F1 are like fucking butter.
In vertical shutter SLR's something properly damped, either by design (higher end motor-drive EOS or Nikon F, or later Contax and Leica) or by weight (Nikkormat, Konica T3), will give no issues.
And by "no issues", I mean 1/15 handheld, or tripod based macro or 200mm-plus tele, with no double images.
Anything slower than that handheld is a bit trite to blame the camera when you get blurry shots.