Well no complaints about the sharpness of the 44m 8 blade, but mine is odd in that it screws onto a MTL3 but wont screw onto a M42 adapter or Pentax camera body.
(Excalibur)
I've got the 44-2 and 44-m, I rarely leave home without one.
(Lloydy)
These models are (or can be) multi-coated:Helios 44-3 (always multi-coated, pre-set, 8 blades)
Helios 44M (both MC and single coated version exist, MCed is rare, A/M switch, 8 blades)
Helios 44M-4 (both MC and single coated version exists, auto, 6 blades)
Helios 44K-4 (K-mount, i believe this model is always MCed, auto, 6 blades)
Helios 44M-5 (both MC and single coated version exists, single-coated is rare, auto, 6 blades)
Helios 44M-6 (always MC, auto, 6 blades)
Helios 44M-7 (always MC, auto, 6 blades)
(no-x)