Front suspension?
For road use, it's heavy, takes the edge off the steering and compresses under braking - making the process floaty and indirect even with heavy pre-load. I wouldn't bother - and if you have lock-out, I'd use it when on roads or on smooth singletrack.
Off-road, it transforms the experience for the better and makes it possible to ride harder, longer. I was an anti-suspension Luddite for years, but the whole off-road experience is better with wrists that still work after 10 miles. I still occasionally go off-road with rigid forks, but I am probably certifiable.
Rear suspension? It's not for me. I do see very good riders riding very fast with full-suss, but I'm not at their level. When I see an average or struggling rider with a full-suss set-up, I find myself wondering whether they wouldn't have been better off saving the weight and cost on a hardtail.