The 98/2 blend is designed for GMAW Spray welding. The high argon content enables the wire to go from a globular to spray transfer because of the ionization potential. the 2% O2 aids in the wetting of the puddle- makes it a lot more fluid. The C-25 mixture is designed for short arc and globular transfer in Mig welding. When the Argon content goes below 83%, spray transfer is next to impossible.(I say next to because I have seen a couple of pulse machines capable of spray welding with C25)
I am not sure of the qualifications of this gas but in Canada, 98/2 is not certified to CWB standards for mig welding on carbon steels because of the oxygen content.It is used for some Stainless Steel welding. I have used this blend and it does a beautiful job when spray transfer mig welding on steels over 1/4 or 3/8 thick. I have also experimented with it using an .035 S-6 wire on 14gauge steel in a very tight spray pattern. needed running shoes to keep up though- got somewhere around 32-34ipm travel speed.

If the robot is being used for higher speed welding as opposed to repetetive or precise welding, I would try the 98/2. If this doesn't work and you would still like to try to get into a spray transfer, maybe try a blend of C-15. another all around good gas.
Hope this helped.