The latest gen AMD cpu's have the full amount of cores, as stated. The one difference is the Floating Point Unit. 2 cores share 1 floating point unit, whereas in normal cpu configs, it is a one for one basis (one core paired with one floating point unit). They are weaker than the Intel, but still good enough, especially for the money. The best performance for dollar chip is currently the FX 6300.
Trinity uses the module system above; 2 cores using one floating point unit. Trinity is a piledriver based chip, same as the FX cpus. Only difference is that it has a igpu and no L3 cache, so the FX chips are better performers. Trinity, Richland, Kaveri, Vishera, Zambezi...are all Bulldozer, Piledriver or Steamroller CPUs.
What do I think of them? As above. I think they are fine. I have an I5 haswell system, but after witnessing friends computers with FX 6300s and the like, I honestly wouldn't care too much if my PC shat itself tomorrow, and my only option was an AMD FX piledriver system to replace it. I didn't see anything to complain about performance wise, and they haven't been overclocked as yet.
Probably burn a bit more power, but the difference is only lightbulb type wattages between them....not enough to care.