Hello harpooninvestor

Firstly, I'm not an expert here but I might be able to shed some light on your comments and questions. 

I tend to look at BitShares and OpenLedger as two different entities. The BitShares exchange (https://bitshares.org) uses the currency bitshares and OpenLedger exchange (https://openledger.io) uses its own currency called obits. I know bitshares (the currency) acts like a quote currency, so you'll find markets like USD/BTS for example and others on the BitShares exchange. I trade regularly on the BitShares exchange and I hold bitshares (BTS) in my portfolio. I have not experienced any big problem with fees per se, but I have not moved too much in or out of the exchange. The fees may be different on OpenLedger but I wouldn't know. On the BitShares exchange there are some currency pairs that have wide spreads, so that is an issue which I'm more familiar with, but like I said I think this is getting better as more people come on board. 

I believe the people who run OpenLedger built their product and services based on BitShares code. So they forked it or created a derivative of BitShares. And this is why the two websites appear to similar when you're looking at the web pages of each. 

Where the two appear to differ is in the exchange trade volume. I have accounts on both and when I observe the OpenLedger exchange I don't see the liquidity that I see on BitShares. OpenLedger offers a number of services besides just an exchange, yet I don't know exactly where their services run parallel with BitShares and where they offer distinctly new or different services. I haven't taken the time to necessarily compare them. 

I'll share a couple links I find valuable...

https://steemit.com/bitshares/@steempower/bitshares-state-of-the-network-2nd-january-2018
This comes out weekly and offers up information you're seeking about exchange volume. It also reports user growth, partnerships, etc. Follow the @steempower blog

https://cryptofresh.com/
This is the blockchain explorer for BitShares. You should check this out even if you're not familiar with blockchain explorers. I like to see what other people are buying. That has helped me see opportunities for my own trading. The site is very user friendly with easy-to understand charts. Info about witnesses (nodes), etc. 

Happy trading to you and I hope my rather novice understanding of this topic is helpful.