ERG training mode Taxc Vortex or Computrainer

I have both a Tacx Vortex and a Computrainer. I am 9 weeks into the 12 week FTP builder and have been happy with my results so far. I have been using the Vortex primarily and been very happy although I prefer the Computrainer on free rides since it feels like the resistance on climbs an descents is slightly more realistic. The downside to the Computrainer is I can’t hold a steady power on ERG mode. On the Vortex it variries from the prescribed power by 1-3 watts usually. On the Computrainer I am constantly going up to 10-15 watts ablove or below. It is getting fustrating. I’m not sure if I need a firmware update on the Computrainer or if this is something I just have to deal with. I am back on the Vortex for now.

My newish computrainer ( about 2011) wattage varies by that much in the erg mode too. 

Suggest you ask the Computrainer people over at Racermate Inc.