On the first count you are correct, they do force you to use there router. However crap and restrictive? Cant say I've had any problems. Not sure where you've got the idea that it restricts port forwarding as you can port forward using there router (livebox). Not so sure on the 5 clients as I've not used it for any more than 4, but to be honest, most people aint gonna be running 5 clients on a home network anyways. The majority will only use 2.