I have the old Toneport KB 37 and am using the Gearbox software. But I recently downloaded the POD Farm software.
The main difference between Toneport and Pod Studio is the software. Toneport uses Gearbox while Pod Studio uses Pod Farm.
They are both similar in terms of the choices of amps and stomp box effects but with vital differences in how they can be used. First of all they have different interfaces, so those who are familiar with Gearbox will still have a learning curve to go through before being able to utilise the Pod Farm.
Secondly, from what I understand, the Pod Farm has both a standalone as well as a VST version. What that means is that Pod Farm will allow you to incorporate the software as a VST into your DAW. Gearbox also has a VST version, but it needs to be purchased separately.
Why is the last point so important? The older Toneport has a disadvantage: when you record your guitar, the tone that you get is permanent. Any changes of tone or setting that you need to do would mean you have to re record your guitars all over again.
Because POD Farm's has a VST function, from what I can understand, what you are actually recording is your CLEAN guitar. POD Farm will put effects on that clean signal to the effect you want. So in case you change your mind about the tone, and you want a different one, all you have to do is change the amp or effect on the POD Farm software, and that particular tone will be heard instead. If you take out the VST from your guitar channel, the guitar will be clean instead.
I will have to further experiment on this, though. But usually with VSTs that's how it functions.
To own the POD Farm software though, you don't have to actually purchase POD Studio. If you have the old Toneport it's good enough. You can then download the POD Farm software at the Line 6 website for free. However, as mentioned in my last reply, you can't have the VST function.