Maximil, I am a recent graduate from the Medical University of Vienna. How come you are interested in post-graduate training in Austria? Vienna is certainly a great city to live in during your university years, but much less so for non-Austrian graduates looking for competitive positions in Vienna (which is basically Austria's only 'metropolitan' region and in super high demand). I can explain the situation as it is for Austrian graduates. As an EU citizen, it should be similar for you.
As far as I know the current situation requires graduates to undergo three years of postgraduate training prior to starting residency (so called 'Turnus'). These positions are typically very unattractive as far as learning is concerned. In many hospitals fresh doctors will basically perform activities that are performed by medical personnel in other countries (blood draws, ECGs, administering infusions, etc.).
However, the Medical Universities have restricted admission criteria a lot, so much fewer graduates are available so hospitals are improving their training programs and from what I heard the situation is improving. Again, this is less the case in the region around Vienna, as demand from graduates who want to live here, remains high. Actually, before starting one would have to register in a 'waiting list' and it took typically 2 years before being able to start 'Turnus' in Vienna. Recently, with less graduates this time has come down to approx. six months.
It is much easier to find a "Turnus"-position in the other Austrian states. Particularly the state of Vorarlberg is actively recruiting junior docs and their salary is typically listed as EUR 68'000 as a first year. From what I heard working conditions are good in these hospitals from a workload standpoint. The nature is also quite beautiful but you are very unlikely to be exposed to any 'cutting edge' technologies or research. I assume this is pre-tax so you would end up with approx. EUR 35,000 - 40,000 during first year.
What I described above it the 'typical' pathway that most Austrian graduates take. There are also three University Hospitals, with Vienna's General Hospital being the largest and most research-intensive. The university hospitals can theoretically train their graduates right away, so Turnus is not required in this case. For most specialties, the competition is very high to obtain such position. I know of one Cardiology resident who had to work in research for four years before being accepted. There is a certain degree of intransparency how these positions are allocated and many people suspect favoritism / nepotism to be quite an issue. Pay is also very low, as well as job security.
Altogether, the situations for post-graduate training is unattractive to moderately-attractive with some signs of improvement. There is also the discussion to transform the current Turnus system into a common-trunk which would be recognized as part of specialty training. I am not familiar with the situation in Estonia, but unless you have very compelling reasons to come here and speak German fluently, I would strongly recommend to research alternative options (US/UK/Australia/New Zealand/Scandinavia)
Good luck !