I’ve had Eir Fibre-To-The-Home broadband for about 2 years now, it has been rock solid and very quick, I’d highly recommend it. I had Virgin Media cable broadband for years before that and also found it very solid and quick, would also recommend. If you have the choice I would go with a fibre-to-the-home option, next best is cable (TV) broadband.
It depends on your location and the availability of providers and services in your immediate area. No one answer will solve all problems due to the piecemeal implementation of services and the multiplicity of retail and wholesale providers, a hodge-podge, a mixum-getherum typical of tech "solutions" in this country.
on a separate note, bear in my mind the following:
1. what's the notice period of current and future broadband provider - in case you decide to switch after the end of your contract
2. if you are switch between e.g. tv cable broadband to phone line broadband - just ensure that the old subscription is cancelled. The new provider may claim that they look after notifying your previous broadband provider but that's not always the case.
3. working from home since March 2020, I've noticed during the conference calls that phone cable broadband with lower max speed is more reliable than tv cable broadband and it's due to their infrastructure (underground vs above the ground) - but I'm outside Dublin region.
I've had no real issues with Virgin, like many of these suppliers, you need a cup of coffee and a lot of patience trying to get through to their contact centre but installation and reliability has all been fine.