Is the amd 4300 worth the extra money or is the 4100 decent enough?I've heard that that the bulldozers weren't that good...
Yes, the FX 4300 is essentially an &updated,& improved, version of the FX 4100. It's worth spending the small amount to get the 4300 over the 4100. In terms of the CPU series as a whole, yes, Bulldozers aren't that great. They're definitely viable though. Remember that the GPU is much more important than the CPU. An FX 4300 + HD 7850 would performing better than an i7 3770k + HD 7750. If you have the budget to up the CPU without downgrading the GPU, then do so. Also consider the older (but IMO better) AMD Phenom II x4 series.
For roughly $10 more you get at least 10-15% improvement on Bulldozer CPUs.
The 4100 is decent enough however I would not be happy myself with a 4100 when if I spend about 10 dollars more I get a new CPU, more cool, more efficient, less power hungry, and faster!
The FX 4100 is decent. If you`re on a tight budget you should just keep the FX 4100. But if you have money lying around, why not? It is not a big difference, but as I said, it all depends on your current economic situation.