One of the joys of having three matched frames is the opportunity to experiment with strings on one frame while having the other two for serious practice and match play. Today I tried another full-poly experiment with Luxilon 4G 125 mains and Solinco Outlast 16 crosses. Unfortunately, results were similar to past experiments with full poly stingbeds. The frames are configured as shown in my signature (modified Pure Storm GTs which are 95" and 16x20). I had the 4G mains strung at 49# and the Outlast crosses at 47#. This seemed reasonable given Luxilon's advice to string "at least 10% lower" than one's standard setup which is 55/51 for my VS/4G hybrid. These tensions are also in keeping with the conventional wisdom that one should string modern co-polys no higher than 52#. 4G/Outlast Full-Poly Hybrid: - Comfort: not bad but not as good as VS/4G for obvious reasons. There really wasn't much difference when hitting the sweet spot. The real difference showed on slightly off-center impacts. VS/4G feels good even when hitting towards the tip. 4G/Outlast felt like a board. But even in the sweet spot the feel was completely different. I can feel the VS/4G stringbed almost grip the ball while the full poly hybrid of 4G/Outlast felt like a board. The feel certainly wouldn't bother a lot of folks but for someone used to softer gut mains those off-center hits were jarring. - Spin: this was the primary reason for the experiment and was extremely disappointing. The idea was that Outlast has an extremely low string-to-string CoF (one of the lowest measured by TWU). And sure enough, the 4G mains slide perfectly well over the Outlast crosses. In fact, a key benefit of Outlast over 4G is another reason for putting the Outlast in the crosses: it's very slippery and very resistant to dents from the mains. Even gut mains will dent 4G crosses over time. But the 4G didn't dent the Outlast crosses. In theory this should have been a spin machine but compared to VS/4G it wasn't even close! TT member ChicagoJack has reported similar results when comparing full poly to gut/poly and this is yet another example. The VS Touch/4G hybrid generates really useful spin with casual ease. Even the most moderate brush across the ball results in amazing amounts of spin. Not so with 4G/Outlast, not even close in any way. With the full poly hybrid I really had to work hard to produce spin of any kind. Slices were completely lame compared to what I get with gut/poly. A really good indicator was pressure shots: with gut poly even if hitting on the run towards the BACK fence and over my left shoulder (I'm a righty) to return a surprise lob I can generate moonball-style, point-saving top spin with gut/poly. With this full poly hybrid shots that would normally dive in with ease sailed long. Another good indicator was serve. With gut poly a VERY casual stroke results in a diving kick serve. With this full poly hybrid serve was a chore when using spin to drive the ball into the service box. The bottom line lesson for me with this experiment and similar experiments in the past: nothing compares to the CASUALLY generated spin possible with gut/poly. I know the conventional wisdom is that polys are the Kings-o-Spin and they certainly are as crosses with gut mains (I've also tried other crosses with gut mains and nothing compares to a slick poly cross). But once again it was abundantly clear to me that yet another full poly experiment couldn't compete with a gut/polyu hybrid for spin (as well as comfort, but at least that's understandable.) Finally, this issue also effects control. On flat shots and volleys the two string beds were close in performance. But on serve and most groundies the gut-poly totally outperformed 4G/Outlast (and other full polys I've tried) because the extra gut-poly spin provides extra control and margin for error. Maybe this whole subject is a candidate for Myth Busters???