Strangely enough I myself am looking to upgrade and came up with that same choice although 1900acs (new version) is looking more appealing now since it is only 10usd more on amazon.
As for my current router it is an old trend net that needs retiring since it is almost 10yrs old TEW-431BRP.
For me the 1900ac was appealing because of its price/performance and its great performance sharing files using its USB3 port attached to a portable hard drive. I have decided to get a dual drive NAS instead so other options might be considered.
1900ACS review on Cnet
http://www.cnet.com/products/linksys-wr ... fi-router/