We recommend that you use L2TP/IPSec as your VPN protocol for site-to-site VPN connections. L2TP/IPSec is more secure than PPTP and IPSec tunnel mode. However, to ensure that you have a secure site-to ...

Even Microsoft suggests that you ditch PPTP and use an alternate VPN solution instead. The argument against PPTP is pretty solid – but the reasons for my doubts about IPSec and L2TP are harder to nail ...