- Extremely rattly and loud. No idea why, but I assume it's because of the extra resonance created by the double-decker design. Any time the engine is idling, you're shaking with it, and you're likely to get a headache in the long term. Don't even get me started about how it leans and kips hitting tree branches on tight corners in Sandymount. I don't generally get nauseous in public transport, but Dublin buses would without fail get me extremely dizzy.
- Terrible seat design and spacing. I'm not a tall person, but there's some rows where I can barely fit my legs. Not to mention the seats tend to bend back with use, giving the person behind you even less space.
- Dirty. I haven't ever seen a single bus without an empty can, bottle, or other packaging. Spilled liquids are common, too. But that's a general Dublin problem - for some reason it's one of the nastiest cities I've seen, people just don't seem to care for it at all.
Just to be clear - I'm not comparing this against an imaginary Perfect Bus. I'm comparing this against existing bus systems I've used and loved (Warsaw, Munich, Berlin, ...).