Hybrids are a very nice arm-friendly set up(if used with a synthetic gut). I use a hybrid setup of Poly in the Mains, Synthetic Gut in the Crosses. It's great. It's very comfortable. To me it feels like a whole Multifilament setup, but more durable. It's got good power, control, comfort. I use a hexagonal-shaped poly, so the spin is good too.
I've never used a hybrid setup of Synthetic Gut in the Mains, Poly in the crosses.
To me, it just doesn't seem common-sensical. We all know that when we break strings, it's almost always the Main string, never the Cross string.
So, you would figure that it makes more sense in putting the stronger string in the Mains and the weaker string in the Crosses. That's why we put the Polys in the Mains and the Synthetic Gut in the Crosses.
And from experience, I almost never break strings anymore because the Poly Mains are so strong. Therefore, I usually end up cutting strings out when the setup loses too much tension after 3-4 weeks.
On the other hand, if I had strung the setup with Synthetic Gut Mains and Poly Crosses, I'm fairly certain i would break my strings within 2 weeks(maybe less). Strictly because the Synthetic Gut in Mains breaks a lot easier than Poly.
So, keep that in mind.