I am testing out gut mains with a poly cross at 60m/57c using Klip Legend 16g and Cyber Flash 17L 1.20mm in a PS 6.0 85 SV. In this setup, the firm feel of the poly was kept and the gut mains added a lot of power and pop to it. 3 weeks into it after a bit of tension loss, the firm and powerful feel changed to one with more bite because the lowered tension allowed for more pocketing and the racquet became even more powerful. The SV with this setup is really addictive to play with. I'd like to hear from other people with opinions on their experiences with gut mains and poly cross, their likes and dislikes.