Really good access point / router?

Can any one recommend a really good access point / router, if possible also supporting upcoming .ac-standard.

I currently have an airport extreme in use, which had issues and seem to have issues again. With a big load (probably just parallel connection and not the bandwidth volume) it seems to crash spontaneously. Since its now a few years old already I thought about a change.

Talking with some coworkers about this it seems like other access point hardware have similar issues. I tried an ASUS access point / router for a short time but its backend configuration looks way more complicated in compare to the airport one.

Price range is not that important, but it should not exceed $200 / €150. Any additional feature like for example USB-Drive-Support is welcome but not really necessary.

What features I actually expect:
- at least 4x Gigabit Ethernet Ports (the better the more, I currently need an additional Switch)
- at least WLAN n-standard
- port forwarding configuration

If possible:
- WLAN ac-standard
- USB-Drive-Support (USB3?)
- WLAN signal intense configuration (power of antenna signal strength)
- Heater (airport extreme can get quite hot)
- low power usage in general (I have seen a Kickstarter project about a touchscreen-driven device which consumed quite a lot)
- dyndns update service