The immediate stand out when you arrive in Cardiff is that they have plonked their rugby Mecca, Millenium Stadium, more or less right in the middle of the city. Basically imagine a smaller version of the MCG being located on Bourke St, it's kind of odd.
As far as guide books went, there weren't any glowing recommendations in regards to Cardiff, but we thought we'd give it a go. In hindsight, we probably could have passed and not missed much.
We took a look at what is probably it's main attraction, Cardiff Castle, which was ok without being too exciting. The Cardiff Bay area was also quite nice, but has nothing on many other waterside areas you could find anywhere in Australia, or no doubt other countries.
Probably the strangest phenomenon we've seen so far came from Cardiff though. In the two nights we were there (admittedly a weekend) we spotted no less than 15 hens nights walking around the very modest main drag for pubs and clubs, with a similarly burgeoning number of stag parties. It was kind of appropriate given the dirty, seedy nature of this area, which kind of summed up a lot of the city.
On the positive side of things we had a good night out to watch the amazing Ghana v Uruguay world cup match, and the hostel we stayed in was excellent (Riverside Backpackers, for those who may visit Cardiff after this wonderful endorsement). The hostel also recommended a similarly quality venue to try some Welsh cuisine where we dined on Cawl (a kind of lamb stew) and Glamorgan sausages (cheese, leek and breadcrumb sausages), both receiving a unanimous thumbs up from the judges.