I use OpenLedger as well. It also seemed confusing to me when I first started using it, but I came to appreciate & be impressed by it once I got over the initial learning curve. I see two advantages to OpenLedger over other exchanges like Poloniex:
It's decentralized, so less trust in central entities is needed (although there is still some centralization in the gateway services used to get assets into / out of the system)
It's flexible in that you can make a market for pretty much anything. Don't see a market for ETH / whatever-your-favorite-altcoin is? Go ahead and make one.
Sadly it's sometimes difficult to trade on OpenLedger because of the low volumes and thin order books. I hope more people will start to use it so that assets become more liquid. I use it mostly for DGD trading since DGD is not on Poloniex yet.
Have you also tried the direct Bitshares and could comment on the difference between the two?
And/or between any other decentralized exchanges popping up (Bitsquares is one of a few)?
OpenLedger is the only Bitshares platform I have tried, so can't offer a comparison with others, sorry. The only other decentralized exchange I have tried is Bitsquares, and I recommend staying away from it. The UI is nice and fairly intuitive, but the trading process itself is quite clunky and can take up to 24 hours to complete one trade in the worst case. It's more akin to a digital version of meeting someone in person to swap assets, rather than what you would typically think of as a cryptocurrency exchange.
I have heard many rumors of an upcoming Ethereum based decentralized exchange called Etherex, but as far as I know it's still under development with no clear timeline for release.
thanks for the feedback on Bitsquares. sounds like it definitely needs some upgrades before worth looking at...