1. Out of the box? I'd say the agent experience is enough. It's a clean UI. Now I don't know what your Task Routing is doing, but there is an SDK that can be used to make a lot of customizations, including your own chat template. I've never had an agent complain about the look and feel about the ECE UI.
2. I've found that the ECE reports (from the Reports console) provides much more meaningful metrics than what you'll find in the stock ECE CUIC reports. You can add ECE as a Data Source and create your own reports, however, it's rather difficult because there's no database schema document. Any historical report in regards to email should be ran from the Reports console within ECE. The reason being is that the stats will reset every 24 hours in CCE and you won't find how many emails are truly queued. If you have a customer whose email volume is very heavy, it's reasonable to believable that emails will sit in the queue for over 24 hours.
3. The Administration console has improved since the old EIM/WIM version 4 and 9 days, but it's not the friendliest of consoles. The learning curve with all the settings and understand how they all work together takes some time.
4. With ECE, you can incorporate...
Messenger applications like WhatsApp
Social media messaging like Facebook Messenger
SMS messaging. We've used Webtext
Webex Teams
I've also used the Web Callback functionality. It's a straight forward feature that works pretty well. It uses the peripheral to make the call, so the call is initiated from the agents phone. Think of it as an outbound preview campaign, but without the option to accept or reject.
5. This is it, really for omnichannel integration into the contact center. At this point, I don't see any reason why anybody would go full blown eGain over just having on-prem ECE. The good thing about ECE is that you can purchase additional features from eGain and "plug" them in like OneTag, CoBrowse, Virtual Assistant, Customer Journey (Solve).
The product has come a long long way. Adam Mermel (Product Mgr) has continually said that they're more or less all in on ECE. I think Adam and his team have done a good job of listening to customers and partners and taking in the feedback. ECE today is already a better product with its current 11.6 ES version than it was with its initial release of 11.5. The product team is pretty committed to improving ECE in version 12 and on. Additionally, Cisco is really pushing Context Services and there are going to be big improvements in version 12. It is pretty nice when you can pull up a customer and see when they've called, emailed and chatted with you, but this is only achievable with CCE and ECE.
We've some really cool work with a customer in Atlanta where we're doing a data dip for chat to verify the customer, returning all this data (for routing purposes) and sending it off to a Virtual Assistant where it'll go to a live agent if the customer chooses to escalate.
I've attached a zip files that contains documents you'll be interested in seeing
