After doing further reading on this forum, it seems the ER604W is the least expensive TPLINK solution for Client to Lan L2TP/IPsec with the BetaFirmware to fix iOS10 issues here:...

https://support.apple.com/en-hk/HT206844 In essence, since R600VPN only supports Client-to-lan VPN via PPTP, new OS versions of Apple devices and computers will no longer work with R600VPN. I'm...