Well I still use D3s's for low light work and with my 200-500 Nikkor. To me they are a bargain. If all my gear was stolen I'd buy two of them.
I also recently bought a D2x which thom hogan reckons is better at base iso than the D3's. I use it with a 20mm f2.8 Ai. The trick is to put a DK17M viewfinder magnifier on the D2x, in fact I put these on all my pro Nikons ie D810, Df, D3s, D2x. Makes manual focussing so much easier.
Had two S5Pro's myself but these days their need for a fuji battery rather than the standard Nikon en-el15 must be a pain. If Fujifilm had developed that sensor further I would have stuck with them. I am often tempted by a D2h but worry about a mere 4Mp. Just not sure how big I could print from that.
I borrowed a D200 but the viewfinder was just too much tunnel-like for me.
D2x is the bargain for me, battery lasts forever too. I also don't think it's as bad at high iso as the web likes to make out.
All the best, Mark