I have a V4 Mega, and do similar riding to yourself, off piste stuff, local DH trails.
I put a Kitsuma coil on it while the Fox air shock was off for a warranty appraisal. It took a few rides to get it dialled in (got bucked over the bars first ride!), but now its setup suitably, there’s no way I’m putting the air shock back on. Completely subjective, but I found that the coil soaks up chatter and rooty, rattly sections better, and seems to offer more traction over rough terrain and when braking. It gave me a tangible confidence boost, and according to strava I’m a fair bit faster going downhill since switching to coil.
The only downsides really IMO, would be that smoother flow trails are more fun on air, and the coil shock bobs more when climbing (though the kitsuma has a climb switch that negates this – you just have to remember to use it)