Originally Posted by Torres
It's not that great. Simple as that. Alu as a cross blows 4G out of the water in terms of stringbed performance. Crisper, better feeling (compared to 4G's dull feel) and allows the gut to slide better for more spin.
Key advantages of 4G over Alu are comfort and tension loss.
If you can afford to restring gut/poly when the Alu crosses start dropping serious tension thus reducing control and comfort then go for it.
For me 4G has been my savior from Gut/Poly Hell when it comes to tension loss, control, and comfort. Other poly crosses can provide decent comfort and better spin (eg MSV CoFocus) but suffer in tension loss and control. Others provide great control and spin initially but then seriously decline in control and comfort.
I agree that 4G crosses provide less spin potential, especially at higher tensions and in dense patterns. Under those two conditions I too would not recommend it at all.
But in open patterns and medium tensions I think its spin is more than enough (my slice can break nearly sideways)and its longevity is absolutely, positively unmatched by any other poly which dramatically improves gut/poly's value for the average rec player who is unwilling or unable to restring after just a few hours of play.
While other polys were viable in fulls beds wrt cost because they were both cheaper and less playable over time compared to gut, 4G seems tailor made as a cross for gut as it comes closest in matching gut's playability and comfort over time. In other words, other polys CAN be used as crosses for gut but don't mesh well with gut's longer term playability.
IMO 4G is the first poly that seems explicitly designed to mesh with gut as a cross when it comes to aggregate comfort of gut/poly vs full poly or even full multi, tension loss, and long term playability.
For "5G" I hope Luxilon solves 4G's denting problem which will significantly improve its spin potential. A thinner guage would be nice too.