When choosing between PPTP and L2TP, keep in mind the following:
Client support: PPTP is supported by a much larger range of clients.
Ease of installation: L2TP/IPSec requires a PKI infrastructure to supply the client and server certificates. This significantly increases the cost and complexity of the deployment. Certificates are not required for a PPTP solution unless you are using EAP-TLS. This makes PPTP deployments significantly easier than L2TP.
Level of security: PPTP provides only data confidentiality (encryption), while L2TP/IPSec provides data confidentiality, integrity, and authentication. Data integrity validates that packets have not been modified in transit. Data authentication validates the authenticity ...