I am great fan of the STV system but I noticed one major problem: it takes very long to count the votes and probably need a lot of people to work in electoral commissions for all that time. When last district will be counted?
This whole process can and should be automated via computer software. Last I checked Ireland still has a lot of IT resources.
For me still electrification of both voting and counting (fortunately more common) process is still science fiction. Although there are examples of countries like Estonia I don't think that larger countries will be able to implement such systems.