I decided to give ABS another chance and I'm seeing some problems with small parts, or small parts in parts.
Here's a couple pictures of what the problem looks like, the grid is 1cm square to give an idea of the size:

IMG_7053.jpgIMG_7057.jpg

The ridges on the cylindrical parts seem to follow the polygonal structure of the model, the square part had no problems.
I used Slic3r 1.7 to slice the STL object, the heated bed temperature was 100C for the first layer, 80C after that. Extruder temperature 240C throughout the print and no cooling fan.
Perimeters were printed at 50mm/s, 60% for small perimeters, 80% for external ones, I used a very short minimum layer time of 4s, but since it moves from one stub to another when printing I would think that gives adequate cooling time between new layers.

I could think of several reasons for the issue, but going through all of them to find the cause(s) may take a while, so if someone with more experience with ABS than me can identify the problem it would be very appreciated.