Fountain pens pretty much all work the same. They all use dye instead of pigment, they all use water based ink (do not write cheques or sign legal documents with a fountain pen for this reason). Comparing different fountain pens is not like comparing a $0.05 bic pen against a $2 gel pen.
The pen I'm using right now is a Sheaffer. Why? It's what they sold at Staples. It's not any better or worse than the Parker I had before. If you're worried about ink costs and different cartridges to use, you can buy bulk ink at Staples and refill cartridges using a needle.