So I come at the question of do I need another hand wing from a guitar player's perspective. How many guitars does a fella need? Just one more.

Anyhow, I'm fairly new to winging (2 years) and I own four hand wings (ArmstrongV2 3.5, Duotone Echo 5, Duotone Echo 7, and F-One Strike CWC 8). I'm very happy with the Armstrong and F-One wings.
I bought the Duotone wings early on and while I like the idea of a boom, the absence of a buoyant central strut is a limitation. Additionally the Echo 7 feels very heavy in light wind (especially in comparison to the F-One 8). Finally the Echo 7 has a 5 cm tear in the fabric of the leading edge that doesn't hold together with sail tape so probably needs professional repair.
So if I remove the Duotone 7 from my quiver, what should I get to replace it? Or should I even bother to replace it? Since I have the F-One 8 I don't need another 7m. Does having an 8m, a 5m and the 3.5m cover me for most/all wind conditions? If I ditched the Duotone 5, should I get a 5.5m? Thoughts about what brand?
Anyway, thanks in advance. Looking forward to some shopping :)