Routing or Drop-IN Mode

I have not yet purchased my Peplink, but I am wondering if there is any down side to running a 380 in Drop in Mode as opposed to Routing? Is there any packet-loss in Drop in Mode?

Drop-in mode is a proven solution and it won’t affect the quality of your network traffic. It allows you add Balance into your network without changing configuration of your existing router and firewall devices.

Using drop-in mode, however, will disable the PPTP server feature.

Here is a link to the basic understanding of Drop-in Mode :