Tacx/Garmin Trainer upgrade - any experience?

[SCD]

Hi hub folk, 

I am currently using an old Tacx i-Flow Multiplayer T1901 in passive mode, with my powermeter linking into Zwift. It is one those units that had the 'UFO' control pad that links to the PC via USB. It needs the PC to control the trainer resistance. The PC is dead and the CDs with the Tacx software are also gone. Resistance is just modulated via wheel speed, so it works.. but soso. I asked Tacx/Garmin for a copy of the software to get the controls going again, but they don't support the software anymore. They offered to have it shipped to them and then give me a quote for a discounted upgrade to one of their newer trainers.

 

Problem is: They don't want to indicate how much of a discount this could account to. And the shipping there and back will take two weeks if I am lucky.

 

The unit is currently working ok for what it needs to do but I need to use it with my expensive bike in order to use the powermeter. And there is no ERG mode or any feedback from Zwift to the trainer neither. Two reasons to make an upgrade attractive. But luxury problems to be frank. And to be without trainer for 2-3 weeks sounds highly unattractive if the offer is pour... the I may better just wait til next summer...

So, has anybody done this yet? How much credit do you get for your old trainer? R500? R3000? 

Any banter welcome, cheers