My first printer, the Prusa I3, was a completely open printer with a 12v heated platform. It printed PLA well and ABS pretty much not at all given the time it took heating up the platform and then the issues with prints adhering to the build platform at all in my drafty man-cave.
Enter the Wanhao Duplicator 4S. It was a completely enclosed printer with a 24v heated build platform and it did ABS brilliantly. It still took time to heat the build platform but I was ok with that....first, because it really did do ABS well, but second as I was NEVER able to get it to print PLA well! No matter what build surface treatment that I tried I could not get reliable print adhesion. I know that I should have been able to get past this but I could not in the time I gave myself so I just printed ABS, brilliantly, I might add.
Now we are in the Ultimaker age and I am largely printing PLA. To me it seems like the stock UM2 is really designed more for PLA than ABS given that it is partially open. In my man cave this results in print adhesion and warping issues so I got a door and a cover for both of my printers. Now I can print either ABS or PLA on either printer.
So what are the benefits of one material over the other? PLA is much, much easier for me to print with on the Ultimaker 2. Print adhesion is more straight forward (clean build platform and hairspray) and things are just so much faster given a build platform temperature of 60 versus 110. The other worry with PLA is that it has a pretty low melting point and I can envision parts being left somewhere and getting hot enough to warp (hot car even though probably not in the UK)!
PLA is also bio-degradable which is both a good thing from a landfill perspective but could be a bad thing if your print bio degrades out from under you! In reality I have seen no evidence of PLA bio degrading in normal use. I even have some shelves under the kitchen sink where they are frequently wet and after more than a year they are just fine.
Finally, and obviously importantly, I think that PLA looks a little more crisp than PLA. I need to document this as it may only be subjective but the combination of this with the speed and ease of PLA has me liking PLA a lot better than ABS. Except.
So what is the quandary? Simply the issue of prints that need supporting material. No matter how I tweak my setting it is still a real pain in the ass to get the support off the PLA prints. The major variables are temperature...need to print as cool as possible so the layers don't rebond and then some slicing settings that control the offset between the support and the working part. With either material I like to print plenty extra support material (inflation distance on Simplify 3D) but the setting that seems to make the most difference is the separation distance between layers but this comes issues on the parts that I have been printing in terms of some stray extrusion strands!
So I am back to thinking about using ABS for prints that require a lot of support material! But I like PLA better. That is the quandary.