My two cents:
then when I was polzovalsa Internet from Kyivstar (and earlier was also a Beeline to the confluence) — to get good speed when connecting through the router, it was necessary to have sufficiently fast router.
The COP, the Internet worked (I don't know how — maybe without these problems) through the VPN, giving an additional load on the router due to the need for encryption/decryption of all traffic. Tariff from 30 megabits on a Linksys WRT-610N was to make the most of 20-24 megabits (2.5-3 megabytes per second).
Specifically to your question — Zyxel P660HN Lite will not work for two reasons:
1) it has no Ethernet connector to connect to the provider network
2) it does not work with VPN (PPTP, L2TP)
Now more than six months connected to the provider "Lanet" and are satisfied. There are no problems with login/password and actually, by the VPN. And external IP address fixed after a reboot of the router does not change.