Thanks for the replies, an example of high powered synthetic guts to make a try? We need durability too
The two synthetic guts (SG) that are too stiff for my personal taste are Gosen OG Sheep Micro and Prince SG with Duraflex. The Gosen can work for some players wanting some durability from a synthetic string, but it usually feels better when tension is lowered by at least a few pounds compared with other softer SG's.
Many SG's are moderately soft. I've had good luck with Babolat, Prince Original (without the Duraflex), Volkl Classic, and my buttery schmoove favorite from Kirschbaum. The Gosen string will likely give you better service life, but it does have a little extra backbone, firmness, "starch", yaddah-yaddah to it.
I generally only put multifiber in somebody's racquet when I'm either replacing an old bed of multi or that player's new top priority is softness and comfort. I agree with our pal
@hadoken above that Prince Premier Control brings very good bang for our buck for that string type. If you want to get a good combo of softness and a string that will last, you can try PPC in 15L ga. if the regular 16 ga. doesn't quite hold up for long enough.