I am using ER605 v1 which is better, but this gateway lacks power for max speed of my internet connection for VPN.

Not yet, I am using PPPoE (VDSL).

@MR.S Hello I have recieved answer from Czech Support Team with iperf test speed. They are not as horrible as mine bude did not reach datasheet values. PPTP -client/server unencrypted...

I know. I have always strange problems:-( I am thinking about Teltonika RUTX10 and Mikrotik RB4011. Maybe it will help. Thank you for your help.

@MR.S Hi, same bad results for me. Now I am thinking about returning device a look somewhere else. I am in contact with support. Maybe they will advice something. I have one week left for returning...

@MR.S This looks nice but i do not think it is in encryption algorithm, because PPTP is thé slowest in my situation.