I have owned (with bombers too lol) a 5 spot ict/horst for a few years.
Built a tnt version up for a few rides with all the same kit off my own bike.
Ridden an ict/horst flux for a week.
Had a short spin on a tnt flux.
Now own a dw flux.
The 5 spot is a stiffer bike than the flux in ict/horst build. When you get on the flux you can feel (and see) the stays moving ever so slightly under load. It feels livelier than the 5 spot for typical xc/old school trail riding.The 5 spot shines on the descents.. especially when those moments crop up where you want to ride as close to your threshold as you dare.Once you get on a fast swoopy trail it will leave you muttering to yourself how good it really is.. something that you might never know until you take it up there. If its used for xc use then the hidden secret it holds might never be found.
Unfortunately for me, i dont ride full on much and like to cruise along on xc routes more than hitting the likes of laggan black and the likes.. so i find the flux,with similar confidence inspiring handling,a better bike to own. I have searched around for an old horst flux for a while but recently ended up buying a cheap dw 2009 flux.
From what i remember from the week with the horst flux, the dw seems as stiff at the rear as the old 2005 version. I may be wrong. The dw as you probably know,is a different suspension design. I wont go into what i like and dislike about the two designs but if i had a choice,i reckon it would have to be the DW. cable routing is a bit more of a faff on dw than their old versions but with how well dw works.. you dont really care about which way a cable is routed! I have a pike on mine wound down to 115. This seems a nice happy medium.
Its really what you plan on using it for.A Flux is something you can live with as your only bike if its mainly xc riding but like mentioned above,dont think this wont descend trails in the likes of Torridon.It will.. possibly better than a lot of 5-6 inch travel bikes with less sorted geometry! Its a tough frame that will give you bags of confidence. If you dont mind having a slightly heavier bike thats not quite as agile feeling on the xc routes.. but you want something that will shine when you take it up a mountain with a build you can be more confident in.. the go for the 5 spot.