The Porta Two HS is quite different, and superior to the Porta02,...
in almost every way:
Inputs/channels:
Porta02= [2]
PortaTwoHS= [6]
Tape speed:
Porta02= Normal,
PortaTwoHS= Normal and High
dbx noise reduction:
Porta02= None,
PortaTwoHS= Standard
Meters:
Porta02= 4-segment LEDs [2],
PortaTwoHS= VU meters [4]
Tape-outs:
Porta02: None
PortaTwoHS: [4]
EQ:
Porta02: None
PortaTwoHS: 2-band fixed
Separate MAIN MIXER and CUE:
Porta02: N/A
PortaTwoHS: Standard
Number of Inputs & Outputs:
Porta02: Minimal
PortaTwoHS: Many
Effects Sends/Recieves:
Porta02: None
PortaTwoHS: [1] Send, [2] Recieves
Inserts:
Porta02: None
PortaTwoHS: [2]
Battery Operation:
Porta02: No
PortaTwoHS: Yes
Similar to design of Vesta-Fire:
Porta02: Not even remotely similar
PortaTwoHS: Vesta-Fire design based on PortaOne/PortaTwo
Compatible with Vesta-Fire tapes:
Porta02: No, [no dbx]
PortaTwoHS: Yes, [uses dbx]
The only downside to the Porta Two [std/HS] is that it's another old 80's vintage machine, the same relative age as your Vesta-Fire, and therefore might require similar maintenance as your Vesta-Fire.
The Porta02, however, is a relatively new item, that should not need maintenance, in normal cases, for many years to come.