RT-N66 or RT-AC-68 to replace RT-N16

Hi everyone!

I am looking to replace my RT-N16 with a new router. I have a lot of data moving around my network through the day, and I suspect that the router is causing part of the issue. Tomato reports that it sits at 90% CPU during most of my file transfers. I work at home and have the following clients connected:

Wired:
PS4
PS3
Google TV
Personal Desktop
NAS / Media Streaming Device (mostly used in network)
Work Laptop

Wireless:
Two phones
Work iMac
My wife's work laptop

Weird custom configs:
-DDNS setup so a subdomain points to my IP
-Static DHCP setup for all my devices on the network
-May use VPN if the router can handle it (I only use it on my personal desktop now, but would love to have it network wide if possible)
-Might setup a separate WAN for the work systems (virtual would be handy, but may use the RT-N16 to handle that)
-A few port forwards

I am trying to decide between the RT-N66 and the RT-AC68 for a new router. I have a love for Tomato since I have used it for years, but would be willing to switch to Merlin's build (which I read a lot of great things about) for the RT-AC68. From what I see, the biggest difference is that the RT-AC68 has more power behind it it seems, not sure if it is worth the extra ~$70

I would love any anecdotal thoughts as well! Thanks.

Edit: Some reviewers suggested just getting the RT-AC66 instead of the RT-AC68 as well, so any thoughts there would be great.