I saw a similar thread but did not want to hijack it, and my requirements are a bit different.
I have a client that wants VPN access for 10 remote users located locally and in different cities.
Users must be able to log into the domain at HQ (Single Sign on with the Windows 7 built in VPN client is a PLUS)
I must be able to specify the Domain Controller as a DNS server at the time of the VPN connection. (Cisco QuickVPN uses the VPN router IP - very unhelpful)
I do not want to statically assign the DNS, if they are not connected to the VPN this will slow them down.
Domain credentials will be cached so they can log on when no internet is available.
My best solution so far has been the Cisco RV series routers with PPTP (I know, the least secure)
Or RRAS (expensive, needs a separate server other than Domain Controller)
What do you guys recommend?