[JJ_SO]

1. HP5 plus for 135 format is a bit grainy. I suggest T-Max400 or Ilford X-P2. 
   
2. it's very clear you didn't adjust the "scan" and went with your "adjusted to taste" of the DSLR version a very contrasty way with poor shadows.
   
3. if film is your thing, get a medium format camera with a decent lens if you want to get close to what DSLRs can do these days
   
4. it's just a terminological thing: You don't call macroshots scans.
   
5. For scans you take scanners, hence the name. These scanners lack of a hardware moiré-filter and get out the maximum of information, while your canon has a filter in front of the RGB sensor. You can run a scan for grayscale only, so you have no loss due to interpolation of RGB pixels.
   
6. The lighting behind the negative also is critical - you cannot have both, usually: good ad balanced contrast or maximum reolution and sharpness. See for "condensor" and "diffusor" light heads of enlargers. Diffusors are less critical for small dust particles because they caus a certain softness. Condensors bringt out the last detail - of hairs, grain, scratches and dust.
   
7. And the smaller the film format, the more perfect your scanning/macrophoto process has to be.